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Big 'ol FAQ on Pirate Radio. Includes plans for am
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From: [email protected] (Jon Kenneke)
Newsgroups: alt.radio.pirate
Subject: Big Pirate FAQ V1.1
Date: 4 Oct 1994 00:32:01 GMT
Organization: CS Outreach Services, Oregon State University, Corvallis, OR, USA
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Version 1.1
The original file had a copyright notice. This notice was not supposed to
be there. This document is FREELY distributable. It is a compilation of
various pirate archives. A version with credits is coming soon. I lost
all of the original information, so it will be a bit.
Enjoy, and sorry about the long lines. That will be fixed in the next
version.
Table Of Contents
-----------------
Introduction...................................................4
Pirate Radio?
The Basics of Pirating and Electronics.........................5
Radio Waves
Equipment Basics
A look at pirating in the U.S.A...............................19
Equipment required and tips
Avoiding the authorities
Programming
Pirating in the U.K. - on the other side......................27
Equipment and such
Broadcasting Locations
Programming
Avoiding Detection and the DTI
An Example of a 'Real' Pirate.................................53
How, Where, and Why
Information of the Ramsey FM-10 transmitter...................56
Amplifier Plans
Improving Frequency Stability
Improving Stereo Sound
Sources for Components
How to Build a Television Transmitter.........................65
Complete Schematics and Plans
A 5 to 45 Watt Amplifier for FM Broadcasting..................68
Complete Schematics and Plans
Build a J-Pole Antenna for FM Broadcasting....................70
Build this great antenna!
A Phase-Locked 15 Watt Transmitter............................72
More Schematics and Plans
BA1404 Stereo Transmitter and BA1404 Specs....................77
The infamous BA1404 stereo transmitter IC
Disclaimer
The author does not condone pirate broadcasting, nor any other related activities. Pirate transmions can interfere with vital communications, such as aircraft and police.
All the plans and schematics have been tested, but the author cannot guarantee their functionali A basic knowledge of electronics is assumed. When in doubt, ask an experienced person.
The material in this book is presented for educational purposes only. Read on and enjoy!
Introduction
Pirate broadcasting has been around for a long time, ever since the early days of radio. Recentlit has gained renewed popularity, as the opportunities in 'legal' broadcasting have declined.
Around the world, shortwave, FM, AM and even television pirate stations have been springing up. Rons for building a pirate station are always a little different, from politics, to just having fu. It does not require great technical skill to start a pirate station. All you need is a lot of enusasm, a bit of time, and maybe a little money. Equipment is readily available from many sources nd ou can even build it yourself.
This book gives several perspectives of pirate broadcasting. Contained within are a collection otories, how-to's, and schematics that cover almost every facet of pirate broadcasting, both in teUited States, and in the United Kingdom. There are
even hints for creating suitable programs for your pirate station.
The construction projects in this book have been tested, and will work if you are knowledgeable careful in the construction. The projects use relatively common components that are available frmmny sources.
Read on, and enjoy Homebrew Broadcasting, a collection of Pirate Radio Techniques. If you have aprojects, stories, or information you wish to contribute for future editions, please feel free t otact the publisher.
The Basics of Pirate Radio: An Informed Overview
FOREWORD
The following is by no means an in-depth introduction to electronics, there are many such books t cover the subject, but intends to explore some of the ideas and concept involved in radio brodating that are relevant to the pirate radio operat
or on VHF FM. In particular we will go a step by step tour of a typical VHF FM transmitter sys starting with the output from the tape recorder or mixer, and finishing with a brief discussino aerials. At each stage we will discuss the pr
os and cons of various alternatives and additional background info, e.g. the use of equipm will be introduced.
Radio frequency signals have AMPLITUDE and FREQUENCY. The frequency is how fast the sil is oscillating from one extreme to the other and back again. Frequency is measured in cycles e second (cp/s), which these days are known as HER
TZ (Hz), 1000 Hz = 1 kHz, 1000000 Hz = 1 MHz. The amplitude is to what extent the signal is illating. LEVEL or STRENGTH can be thought of as meaning the same as amplitude. Amplitude can b easured in Volts (V). There is more than one way
of measuring amplitude.
INTRODUCTION
What we are trying to do is get information from one place to lots of others. I'm using inforion here in a wider sense, meaning speech, music, etc., rather than phone numbers local haidesers or whatever. Now I'm going to assume we're
going to use radio broadcasting to achieve this, which immediately rules out things like sting on top of tall buildings and shouting out really loud. We'll also assume we've got this if in the form of an audio frequency signal, i.e
. what comes out of a tape recorder or an audio mixer. You can't transmit audio frequency signa very easily so what we can do is import the info in the audio frequency signal onto a higher frqecy carrier signal. Two ways of doing this are
AMPLITUDE MODULATION and FREQUENCY MODULATION (AM and FM).
In AM the amplitude of the carrier is determined at every instant by the amplitude of the ao signal, the carrier frequency remains constant. In FM, the frequency of the carrier is detemnd at every instant by the amplitude of the audi
o signal, and the carrier amplitude remains constant.
Frequencies between 30 MHz and 300 MHz are known as Very High Frequencies or VHF. This corronds to wavelengths between 10 m and 1 m. To convert between wavelength and frequency use h formula: Wavelength (in meters)=300 / Frequency
(in MHz).
FM
There are two sorts of FM, known as Narrow Band FM (NBFM) and Wideband FM. They differ by tmaximum allowable frequency shift of the carrier when the transmitter is fully modulated. Ti frequency shift is known as the DEVIATION. Leg
al CB radios use NBFM with a maximum deviation of 3 kHz. Wideband FM is used by the national brcasting companies for radio broadcasting and for studio to transmitter links. The standard maiu deviation for FM radio broadcasting in Europe is
75 kHz. There is no simple way to set the deviation of a transmitter without a deviation meter wh is an expensive piece of test gear. Probably the best way to do this is to vary the leve fthe audio signal going into the transmitter
(TX) and listen on a receiver, until your signal sounds about the same loudness as the other gal?) broadcasting stations. If you use too high a deviation you'll use a bigger than necessary hn of the radio spectrum and be more likely to ca
use interference with others, which will make you even more unpopular with the DTI.
The police use NBFM as well, which is why if you listen to them on an ordinary FM receiver, whics wideband, you can hear more than one channel at a time.
CHOOSING A FREQUENCY
If your first action could be to reach for your receiver and tune trough looking for a blank sp, think again, for a kick-off the FM broadcast band is 88 to 108 MHz. What stations you can reev is determined by where you are, as well as by
the nature of and positioning of your aerial. If you look our old friend the Maplin catalogue wfind a list of the frequencies and locations of all FM broadcasting stations. What it doesn't a, of course, is the frequency of existing pirates
. TX Magazine gives a good rundown of these. Armed with this info you should make a list of afrequencies in use in, say, a 50 km radius. If you write to the BBC or IBA's Engineering Info fices they'll send you service maps of where their
TX's are meant to be able to heard. Then its just a question of finding a big enough gap betw stations, with the proviso that your station shouldn't be nearer than 200 kHz (0.2 MHz) to the feuency of any existing station. This is no problem
as the band is half empty. Also don't choose a frequency which is 10.7 MHz away from any other ation as for complex reasons (which involve the use of 10.7 MHz as intermediate frequency i M receivers) reception will be hard for people lis
tening to you and/or the other station.
Now let's take a little stroll through the whole system.
TAPE OR LIVE
What we are going to feed to our TX? The obvious possibilities are:
A) A tape or cassette player.
B) Live, either directly from the mixer or via some kind of link from studio to TX site (highly remended).
TAPE. This is the safest approach in that you can put a tape on and then retire to a safe distan Links are now being traced and studios busted, and some of the biggest pirates (e.g. the LWR) aeging back to taped broadcasts. If the DTI trace yo
ur transmission and turn up all they can do to confiscate your tape player, TX and aerial, i.e. norests (unless they catch you changing the tape).
Its also the most inflexible alternative as tapes will have to be prepared in advance. Time cks, if you're into that, will be difficult and live phone ins are right out.
Give a little thought to your choice of tape recorder, as it will probably be the weakest link terms of sound quality. In an old clapped out one the heads will be worn flat. Maybe you can ue 'Walkman' type of player, which are small, can b
e battery powered and have an OK sound quality and are cheap. An amateur radio rally I was at retly were selling off very slightly damaged ones for ?2 each. To reduce 'noise' or 'tape hiss' nsch recorders, if you're doing programs with quie
t passages, you can use a circuit known as a Dynamic Noise Limiter (DNL), which is placed on toutput and cuts off the 'noise' just in quiet pauses. DNLs are sometimes used in the soundtrcsof old films. You can find a DNL circuit in part
of the 'Audio Embellisher' project in the Jan. 84 issue of 'Elektor' magazine.
If you want to go upmarket you could use a proper 1/4" reel to tape recorder, though few pirates. The latest and greatest is to use 'Stack machines' which will change the tapes for you.
Whatever you use get one that can be battery powered as you may not always have access to maipower.
MONO OR STEREO
The advantages of mono are that the TX is kept as simple and cheap as possible, and you don't n as much power as on stereo to get same result. The disadvantages are you don't sound a professional, quite small pirates are now using
Stereo Encoders, and maybe people might dial past when the red stereo light on their receis doesn't flash. With stereo the listener can get quality the same of legal stations. Weigh gist this is the extra cost, extra circuitry an
d more output power needed for the same signal.
What you need is a STEREO ENCODER, which combines the left and right stereo signals into a gle composite stereo signal which is then fed into your TX.
For those interested a brief description follows. The left (L) and right (R) signals are fed ina summing and differential amp to get a L+R and L-R signal respectively. The L-R signal is mixe i a balanced modulator with a 38 kHz sub carrie
r to produce an amplitude modulated double sideband suppressed carrier signal. The 38 kHz signis derived from the same source as the 19 kHz pilot tone. The composite output is formed by mixigte L+R signal, the sidebands containing the info o
f the L-R signal, and a bit of 19 kHz pilot tone. The pilot tone switches on the STEREO DECODERn peoples' receivers.
Back in the receiver, once the stereo decoder has extracted the L+R and L-R signal the origi left and right signals are easily got by (L+R)+(L-R)=2L (L+R)-(L-R)=2R.
The reason L+R and L-R signals are encoded rather than L and R is so that a mono receiver can jusemodulate the L+R bit and ignore the rest of the signal. If L and R signals were encoded a mn eceiver would only be able to hear the left chann
el. The 19 kHz pilot tone is usually got from a crystal oscillator, to be quite accurate and stablA crystal resonating on 4.8640 MHz is convenient as 4864 divided by 2 eight times is 19. This ca aily be done by digital logic chips, but its hig
hly unlikely that you'll be able to buy a 4.8640 crystal off the shelf, so you'll have to have omade for order.
It doesn't matter if you didn't understand all of the above but one thing is important. The ndard FM broadcast audio bandwidth extends only to 15 kHz and stereo encoders are designed to asm this figure. If you put signals into them with
frequencies above that the L+R signal and the lower side band of the L-R signal could spreadto each other and you will get a right bloody mess.
With a tape recorder you can't really get over 15 kHz, but if you're live its quite possible. that case you need a LOW PASS FILTER on each input to a stereo encoder. Maplin has a hig ulity design. The pot could be replaced with a
500k resistor to wire the circuit permanently for max. roll off. If you're using a link between dio and TX and you want stereo you'll have to know the bandwidth of the link. If its 53 kHz =8+15) or more you can use it after the encoder.
Otherwise you'll need two links and have to encode at the TX end.
PRE-EMPHASIS
In a typical audio signal the high frequency sounds have less energy than the low ones aso produce less deviation of the carrier. This in turn makes them susceptible to noise we received. To avoid this high frequencies are boo
sted before being transmitted by PRE-EMPHASIS. In the receiver the frequencies are cut by theme amount by DE-EMPHASIS. So the overall frequency response of TX to receiver stays flat, but th lvel of background noise is reduced a lot.
Pre- and de-emphasis networks are characterized by their TIME CONSTANT. In the USA the stand is 75 us, but in UK its 50 us so anything designed or bought from there needs slight modificain
In a mono TX the pre-emphasis network can be built into the front end of the exciter. For a sterTX such a network must not be in the exciter or it'll play hell with the composite stereo signlfom the encoder. Instead you need 2 networks,
one for each channel, on the inputs of the stereo encoder. They're actually often built inthe studio encoder.
COMPRESSORS AND LIMITERS
Compressors and limiters operate on the same principles, but their effects and the reasons for ug them are completely different.
A compressor compresses, it reduces the DYNAMIC RANGE of its input signal. This means as the in amplitude varies over a certain range, the output amplitude varies only a fraction of that rne
A limiter passes its signal unchanged till the input amplitude reaches its THRESHOLD. At thpoint the limiter prevents the output increasing much by compressing its input much more strogythan in compressors e.g. 10:1.
Some American music stations and some pirates compress their programs to make it seem ler and more upfront than other stations. This occurs because the compressor keeps the average eel of the signal high, even in quiet parts of the
program. The flip side of this is listeners can soon get 'listener fatigue' as constant compresn can become boring and irritating to the ear, as if the music were rammed into it!
Compression has other uses, you might compress your program as you transfer it to tape totop quieter bits fading into background tape hiss when played. The process of recording n laying does this to some extent anyway. Don't co
mpress the output of a tape recorder as it'll make tape noise worse. Guitar effect units, labell compressors, are unlikely to be much use. Compressors intended for use in home studio rcring are worth experimenting with. A stereo co
mpressor with a 2:1 characteristic can be simply constructed around a NE571 IC.
Limiters are used to stop a signal's amplitude going over a certain level. E.g. when ting a master disc in record manufacture, large PA systems at gigs to stop loudspeakers blowigeery time someone burps in a mike and, surprise
surprise, in broadcasting. In FM particularly, as the signal level increases so also does theandwidth of the transmitted signal, risking interfering with other stations. With tape inptt the TX its different the output is inher
ently limited by the recording process, no limiter needed. With live input to the TX itifferent. Though you might set the levels right to start, along comes a loud record or voice adyu could be interfering with the next station. Us
e a limiter.
Any limiters based on 2 back to back diodes is a little more than a guitar fuzz box and will so like one. A suitable high quality limiter was described in the May 83 issue of 'Electronics Toa'International Magazine.
THE OSCILLATOR
At the heart of everything is the OSCILLATOR that generates the VHF signal. The frequency ohis is modulated by applying an audio signal to it. The most common way of doing this is usin n or two VARICAP diodes. When a varicap diode i
s operated with a reverse bias the capacitance of the diode varies with that bias.
The diode(s) is/are connected to a frequency determining part of the oscillator. The audio sig is connected across the diode to achieve frequency modulation. Also by varying the DC reverse ba the oscillator can be fine tuned. The higher
the voltage, the lower the capacitance, the higher the frequency.
The VHF signal can be generated directly, or the oscillator can oscillate on a lower frequene.g. a third or half that desired and then followed by a TRIPLER or DOUBLER stage. There are he main types of oscillator:
a) Variable Frequency Oscillator (VFO)
b) Crystal Oscillator
c) Phase Locked Loop oscillator (PLL)
VFO's
These are simple oscillators which can be built round a single transistor. This can be a Bipr Junction Transistor (BJT) or a Field Effect Transistor (FET).
The problem with oscillators based on BJT's is that the frequency is too dependent on the tempture of the transistor. i.e. a few degrees temperature change will result a significant chang i transmitting frequency. For this reason oscillat
ors based on BJT's are UNSUITABLE for serious use as a TX. FET's don't suffer from this probleo badly, so they can be used, but you should still bear it in mind.
The FET's will heat itself up slightly, and other bits of the TX, like the power amps, will beir old pumping heat out, and are usually built into the same case as the oscillator. The frequnywill drift most when the TX is first switched
on as all the components will be at the same temperature as the air outside the TX's case, this known as the AMBIENT TEMPERATURE. After the TX is turned on the heat from the amps will war h air in the case directly or indirectly. As the F
ET warms the frequency will drift a bit. When heat loss equals heat gain you get THERMAL EQUILIBR and it won't drift more. Keep your TX out of drafts to avoid messing this up. If you have fequency counter plug it in to a dummy load and
see how long it takes for the frequency displayed to settle down, maybe about 15 minutes. If yoave time you can arrive at the TX site early and run your TX for the warm up time with no inpt o a dummy load. This avoids listeners who tune i
n immediately having to retune as your frequency drifts.
CRYSTAL OSCILLATORS
This is also simple oscillator but incorporates a crystal into the frequency determining networkhere are various types of crystals (fundamental, 3rd overtone, 5th overtone etc.) and various wy f using them (series mode, parallel mode) but the
ir basic properties are the same. They're resonant on one frequency which is determined by thrystal's characteristics when made. This is their problem, whereas a VFO's are not very sale crystal oscillators are too bloody stable a
nd it's a job to get enough deviation. You'll probably lose the higher frequencies of your pram and stereo is right out. Also chances are you'll have to get a crystal made order for your deie frequency so if you want to change it you'll ne
ed a new one.
PHASE LOCKED LOOP (PLL) OSCILLATORS
The way its done properly is with the phase locked loop oscillator. This combines these of tuning and wide deviation of a VFO with the frequency stability of a crystal oscillator I works thus: A crystal oscillator is used to p
rovide a reference frequency. This is digitally divided by logic chips to a relatively frequency, say 25 kHz. A VFO provides the output, which is also digitally divided to give ante relatively low frequency. These two low frequen
cies are presented to a PHASE COMPARATOR which basically decides which frequency is higher comparing the phases of the two signals. The phase comparator generates an ERROR VOLTAGE whih s connected back to the input of the VFO through
a low pass filter. This is the loop bit.
If the VFO is running too fast the phase comparator decreases the error voltage so as to slow iown till the phases at its input are the same. If its running too slow the error voltage sincreased to speed it till the phases are the
same. All this happens instantaneously of course so the output frequency remains constant.
In this way the temperature stability of the VFO isn't important and it can be built round a BJTs its output frequency is phase locked to the crystal oscillator, and the frequency is very good
Two more things to explain. How do you change the output frequency? By making the VFO'ivider programmable. Say its set to divide by the number N. The phase comparator is a simple mne sort of soul, concerned only with equalizing t
he phases at its inputs, it doesn't know what's really coming out of the VFO, which is N times tdivided reference signal. Because this signal is so low compared to the VFO frequency N can be aeto have hundreds of different values, givin
g hundreds of different output frequencies from the VFO. So changing the frequencies is jusa matter of clicking some little switches.
Hang on a second, the VFO is being frequency modulated by the audio input, so its frequency any given instant depends on the voltage of the audio output. We don't want this variation o the VFO's frequency to be ironed out by the PLL
system, so we 'iron out' the error voltage from the phase comparator, so it just contains e underlying trend rather than what's happening any split second. This is purpose of the low ps filter.
The system can be simplified by leaving out the dividers. If this is done you end up with an out frequency determined solely by the crystal. You've still got the wide deviation capability fcourse, which distinguishes this system from one
based on a simple crystal oscillator. This sort of fixed frequency oscillator is used for thi like wireless mikes and could be used for studio to TX links. Programmable PLL oscillators aeued in all manner of professional communication e
quipment, including broadcast TX's.
BUFFERS
Any oscillator, regardless of its type, is followed by a buffer. This is usually one or two tsistors operating in what is known as class A mode. Its function is to protect the oscillator fo what is going on further along the circuit,
especially from changes in its 'load' as the following stage is tuned. The combination oscillator and buffer together is called the EXCITER and is a small but fully fledged TX mll in respect to its output power. Typical val
ues are in the region of 100 - 500 mW.
AMPLIFIERS
To increase the power output of our fledgling TX we need to add an amplifier. Obviously we arelking about radio frequency (RF), not audio amps. RF amps have certain important characteristis
a) Bandwidth
b) Gain and maximum power output
c) Input and output impedance
BANDWIDTH. This is the range frequencies the amp will amplify properly. The bandwidth isultimately limited by the characteristics of the active devices in the amp (i.e. transistoso valves), but more specifically by its type, LI
NEAR or a TUNED amplifier.
A linear amp will amplify quite a large range of frequencies and they have a good bandwidth, conly 1.8 - 30 MHz which covers all of the amateur shortwave broadcast bands... no good for a VFpirate, but could be useful for a AM pirate. They
operate in class A or B mode and have the advantage that they don't need adjusting when the freqcy is changed. Their disadvantage are they're more complex and dearer than tuned amps and are mc arder to design, requiring extensive knowledge o
f the transistors round which the amp is constructed. Linear amps for VHF are uncommon.
Tuned amps only amplify a narrow band of frequencies, they have a small bandwidth, centered one frequency which is determined by the TUNED CIRCUITS in the input and output networks of the m. Tuned circuits have a RESONANT frequency. Thi
s can be adjusted by variable capacitors known as trimmers, to the desired frequency.
The amp will produce max. output when the tuned circuit resonant frequency is the same as thnput frequency from the exciter. Tuned amps often operate in the class C mode, which is mr efficient than A or B. This means more of the p
ower being drawn from the battery or whatever turns into watts up the aerial rather than heat tamp. They are relatively simple circuits, and are easier to design. The bandwidth is a tradeof with gain, the wider the bandwidth, the less
the gain. The disadvantages of a tuned amp is of course you have to tune it to the frequency yoe using and if you change the frequency you'll have to retune to maintain the gain of the am.
GAIN AND MAXIMUM OUTPUT POWER
The POWER GAIN (as opposed to a voltage or current gain which is different) of an amp is defi as a ratio: Power gain= Output power / Input power, and is a measure of the amps ability tomk its input bigger. Power gains are often expres
sed in DECIBELS (dB) which are defined:
Power gain (dB) = 10 log(Output power / Input power).
Amps also have a max. output power. When this is reached increasing the input power wo result in more output power and may damage the amp.
In the case of single stage (i.e. one transistor) class C tuned amps the gain and max. outppower of the amp is basically the gain and max. output power of the transistor. Knowing these w a calculate the power necessary to produce the
max. output power. e.g. lets consider the popular MRF237 transistor. According to the makers' dataeet this has a max. output power of 4 watt and a gain of 12 dB. First we've to convert the anin dB to ordinary gain: Gain=10^(gain (dB) /
10) for example: Gain=10^(12/10) = 10^1.2 = 15.8 Input Power = Output power / Gain =/ 15.85 = 0.25.
So for 4 watt output power we need 250 mW input power. Most exciters can manage this, he the popularity of the MRF237 in the first amp after the exciter. The joker in the pack is tha l these figures are for a frequency of 175 MHz, t
hat on which the transistor was designed. You can't predict what happens at 100 MHz and have to eriment.
The MRF238 has 30 watt output power and a gain of 9 dB, so it needs 3.8 watt input powerhis can be had from the MRF237. That's how the makers (Motorola Corpse.) planned it.
INPUT AND OUTPUT IMPEDANCE
Impedance is the alternating current (AC) version of resistance.
The standard impedance of exciters and inputs and outputs of amps is 50 . The impedance of theput and the output networks of an amp is altered by the tuned circuits which you recall also tn the circuit in a tuned amp. The INPUT IMPEDANCE
is important as it effects the LOAD the amp has on the stage before it. Max. power is transferred tween stages when the impedance of the output and input are equal. If the impedances aren't eqa MISMATCH is said to occur and in this case some
energy is reflected back from the input of a stage into the output of the preceding one, where s wasted as heat.
THE VSWR METER
Some of you may know that we can use a VSWR meter (also known as Voltage Standing Wave Ratio mr, SWR meter or a Reflectometer) to detect mismatch between TX and the aerial, but a VSWR mete sjust as much at home doing this between amp sta
ges. VSWR is the ratio of the forward (or incident) and reflected power. Except for dear ones theork the same. The switch is set to forward or the SET button is pressed. The knob is then adjuse o make the meter read full scale. The switch is
then set to reverse or the button is pre-released. It now indicates the VSWR. A VSWR of 1:1 perfect (no reflected power) and so unlikely. One of 00:1 shows all the power is reflected bc nto the amp, you'll get this with a VSWR connect
ed to the amp output with nothing on the VSWR output (unless its got a built in dummy load). You'also get it if there's a short circuit in the VSWR meter. In either case switch off IMMEDIAEYor you'll blow your power transistor.
The point of all this is to get the max. power output from the amp into the aerial, instead of at TX and a bad signal.
To tune such an amp you need a load connected to the output (or it'll blow up). We could uan aerial but this introduces an extra unknown quantity... the characteristics of the aerial A well as the fact that we'd be broadcasting. W
hat we need is a DUMMY LOAD.
THE DUMMY LOAD
This is basically a resistor, made so it presents a load to the amp's output independent of quency (unlike the aerial). The 3 things about a dummy load we're interested are:
a) It should be suitable for the frequency we're interested in, about 100 MHz.
b) It should be rated to take the power we're trying to make.
c) It should have a resistance of 50 to match the output network of the amp.
When buying ask for one for the 2 meter band, amateur radio, centered on 145 MHz. Most t gear for this band will work on frequencies we're interested in.
The amp should first be tuned with reduced input power and supply voltage. Adjust the networor the best input match (lowest reading on a VSWR meter connected to the input side) and ajs the output trimmers for max. output power. Be su
re the extra power is in the frequency you want and not in the HARMONICS. Check with a wave metemore of this coming up). Another VSWR meter can be used for a relative indication of the outptpwer, or the RF PROBE will give an absolute in
dication. The pairs of trimmers are very interdependent, adjust one and you'll have to adjust e other, and so on.
This done, if all OK, increase the input power by increasing the voltage supply to the previostage, and the voltage supply and repeat the tuning. Do all this a few times till you reach h required levels. Listen on a nearby (but not to
o near) receiver. The signal should be in just one place on the dial with no funny noises or mlations going on. Check with a wavemeter. Altering the trimmers and varying the input power and sply voltage should result in smooth variations of
the supply current and output power with no steps or jumps. The exception is, as the input powers reduced at some point the amp will switch off, a characteristics of class C amps.
To vary the supply voltage you need a Variable Stabilized Power Supply Unit. If you can't ghold of one you could build one. They're not expensive and are well handy, and give you sm experience, if needed, of electronic constructi
on.
HARMONICS
Harmonics are multiples of the transmitting frequency. For a frequency of 100 MHz, thfirst harmonic, known as the FUNDAMENTAL, is 100 MHz, the second is 200 MHz, the third is 0 MHz etc. They're produced as side effects in v
arious parts of the circuit and will interfere with other users of these frequencies if let esc from the TX. Known as RADIO FREQUENCY INTERFERENCE (RFI). Tuned class C amps don't amplify harmnc, as they're out of the range of the amps abil
ities. But the use of class C means that harmonics are generated by the amp along with the desd frequency. The strongest ones (apart from the fundamental) from such amps are usually the tid then the fifth etc. The amplitude of harmonics
is minimized if the output networks are tuned
properly, but they're still there. Oscillators and buffers can also make harmonics if not set uight.
WAVEMETERS
To detect harmonics we need an ABSORPTION WAVEMETER, usually called just a wavemeter. Or wan use a GRID DIP OSCILLATOR (GDO) or a gate dip oscillator, both of which are known as DIP MEES
Most dip meters have a switch which turns them into wavemeters. A wavemeter has a tuning knocalibrated in frequency, a meter showing signal strength, and some kind of aerial. You hold h aerial near a coil in the bit of the circuit yo
u're interested in, and tune the wavemeter. It shows how much signal is present on the frequencies own in the scale. So you can see what frequencies are being generated in that part of the cici. Ideally you'll just find the fundamental,
unless the circuit is a frequency tripler or something.
If you buy a wavemeter be sure it covers the right range, from below 100 MHz to get the funental to above 300 MHz to get the third harmonic.
Even with all tuned right you're still going to have some harmonics generated by the lastage. A sensible pirate won't let these reach the aerial, e.g. if you're using a frequency of 103 MHz the third harmonic us 307.05 MHz which happ
ens to be that used by USAF Upper Heyford's Control Tower. You might think this is funny but ywon't stay on the air for long. To stop harmonics reaching the aerial we need a BANDPASS FILTER
Each amp bumps up the power some more, because the transistor in each one can only supply so mugain. So if you're the proud owner of a 5 watt transmitter and you're offered a 1000 watt amp it ueless as you'd need probably 100 watt input to d
rive it so you'd need amps in between.
To tune a series of amps on your TX you must break in, physically if needed, to tune each oat time. Do this by unsoldering components and soldering in short bits of coax with plugs oconnect to dummy load and VSWR meter.
BANDPASS FILTER
This filter only allows through a narrow band of frequencies, i.e. it has a narrow bandwidth, a d one would be less than 1 MHz. It needs standard 50 input and output impedance and be able to tk power you're using and be tuned to the frequenc
y you want to let through. Other frequencies are reduced drastically, by an amount known as IRTION LOSS. It reduces also the desired frequency slightly. To keep this loss low bandpass fitr for high output powers are usually pretty chunk
y numbers.
Pirate gear doesn't have this filter built into the final stages so if you need one you have tdd it on. It needs a well screened case to stop harmonics leaking out. In fact your whole TX sol be well screened for the same reason. Say e.g.
you used a shoebox and had your oscillator on a third of a frequency of 92.25 MHz you could be infering with pagers of a local hospital as they use 31.75 MHz. Proper screening and a bandpass itr will eliminate such possibilities.
CONNECTORS
As you may have guessed you can't use any connectors on VHF as they have to match the amp afeeder. Use BNC or the UHF series.
UHF is best for higher powers as you can get a wider cable into the plug. N type is also goodt more expensive.
FEEDERS
So you've got your nice clean harmonic free signal coming out of your bandpass filter... we're the home run. All that's left is to get the signal up the aerial feeder to the aerial and er away. BUT the aerial cable needs to MATCH the TX
's output stage at one end and the aerial at the other. The cable like the TX's output, theonnectors and the aerial has an impedance and to match this should be 50 . It also needs a LO LSS or your watts will escape as heat. Not the
same as a bad VSWR where you lose energy in the TX, a good VSWR does not mean the cable's o.
Decent cables for short runs are UR76 and RG56U. For longer runs or higher powers use UR67.
AERIALS
At last, the aerial! You can run a pirate knowing a little of TX's, but if you know notg of aerials you'll have a few listeners. So you must read a book on it. I recommend 'The w Meter Antenna Handbook' by F.C. Judd G2BCX. Lot'
s of it isn't useful but he goes into things like propagation, matching, VSWR in better detail. Athe dimensions he gives are for the two meter amateur band, centered in 145 MHz. To convert toohr frequencies all dimensions (including diamet
er of aerial element etc.) should be divided by your frequency in MHz and then multiplied by 145POLARIZATION
One thing to decide is what polarization to use. The main ones are HORIZONTAL and VERTICAL. Tomplify you can say a horizontally placed aerial produces horizontally polarized radio waves ad vertically placed one vertically polarized one
s. To receive a horizontally polarized signal you need a horizontally polarized aerial, andor vertical one you need a vertically polarized aerial. Most receivers on FM have horizontal olarized aerials, but all car aerials are vertic
ally polarized. So what polarization you go for depends on the audience you expect. E.g. on Suy afternoon you'd expect people at home so use horizontal, while in rush hour you might favor vrial. You can build an aerial which splits the pow
er between both, as used in legal stations, known as MIXED polarization. But the effect of radio es bouncing off buildings etc. tends to twist the polarization of your signal from horizontal t etical and vice versa, so your signal could stil
l be picked up by the wrong aerial.
Your transmitting site will affect you choice of aerial. In the middle of the area you wanto cover you'll need an OMNIDIRECTIONAL aerial which transmits equally each ways, while outsid or coverage area you can beam the signal in with
a DIRECTIONAL aerial.
The simplest possible aerial for VHF is known as the HALF WAVE DIPOLE. The elements can be b of thin aluminum or copper tube.
The impedance is about 75 which is close enough to 50 to be fed from 50 cable without too mupower loss. A half wave dipole used vertically is omnidirectional, but when used horizontally i as a fig of eight coverage which isn't very usef
ul. Also a dipole needs a balanced feed. You need a BALUN (BALance to UNbalance) transformer. Te can be easily made out of bits of coax cable.
If you don't do this power will be radiated from the feeder. An aerial with an impedance gtly different from 50 needs an IMPEDANCE TRANSFORMER also made out of bits of coax cable.
Before going on air get a low VSWR by adjusting the position of the aerial and any adjustable ces. Aim for 2:1 or less. Use low power into the aerial when tuning it up and adjusting, if usin a100's of watts and a bit came off in your hand t
he VSWR could be so bad as to blow the final transistor. For the same reason check the continuiof the aerial with an ohmmeter before plugging in, to be sure its what its meant to be, either hrt circuit or an open one, depending on the ty
pe. A dipole should be an open circuit.
SITING
Siting is very important. Height is the main factor, even more than watts! Since VHF radio ws go almost in straight lines, 100 watt in your front room will only reach your neighbors, whil 5watt up high and unblocked will go 10 km's or m
ore. The waves do bend a bit so you'll cover more than you can see but its hard to say how much.eration of a Pirate Radio Station
A look at Pirating in the United States.
PREFACE
It is the opinion of the author that many pirate radio stations are founded upon the principle oovelty. That is, their founders either find it amusing to inch over the lines of the law, or thygt a certain kick out of doing something to make
themselves different from their peers. Such stations seem unworthy of the label, "pirate radio stan."
In a world of increasing regulation and control, deviance from established modes of behavior is erated less and less. New ways are constantly being discovered by the government to discourage eint behavior. The broadcast community is already
regulated by the government and extremely limited in its ability to present alternative expression Pirate radio stations enjoy an unfettered ability to present alternative ideas and music and thsae a source of free expressions not carrying the g
overnment stamp of approval.
The operation of a pirate radio station is likely to create some controversy if its audience is stantial enough. This controversy is likely to attract the attention of the authorities who arels than happy when during the course of exercising
their First Amendment rights, people present ideas not approved of by the establishment. Thus, ithooves those who would operate a pirate radio station to prepare for the inevitable attempts by telw enforcement community to apprehend the responsi
ble individuals and to shut the operation down. This exposition is written with the goal of makingw enforcement's objectives just a little bit more challenging to realize.
Careful choices regarding the station location, duration of broadcasts, time of broadcasts, and quency of broadcasts need to be made in order to minimize the chances of being caught by the autoiies.
Under no circumstances should you ever attempt to operate a pirate radio station from a buildingu regularly frequent (e.g. home or office). This is asking to be caught. You should choose betwe peration from a vehicle or man-portable operation
. If you choose to broadcast from within a vehicle, several factors should be considered when choog a broadcast location. In addition to the obvious goal of maximizing your elevation for good sga propagation, you should select a location that i
s well hidden or not likely to arouse anyone's suspicion and you should consider any difficulties t may come up should you need to leave suddenly and quickly.
The location you broadcasts from should not arouse the suspicion of any passing vehicles. An id location would be one that is well hidden from all roadways and far enough away from any buildig o as not to attract the attention of their resid
ents. In addition, there should be more than one path away from your broadcast location should neeor a hasty retreat become necessary.
In order to locate "undesirable" radio transmissions, the authorities will utilize direction fing (DF for short) radio equipment. Direction finding equipment utilizes a highly directional antnacoupled to a tuner and a field strength meter.
After the desired frequency has been selected with the tuner, the operator rotates the DF antenna ul he obtains a peak reading on the field strength meter and then notes the heading the antenna ispited in. Next, a vector is drawn on a map beginn
ing at the operators current location and extending in the direction of the DF antenna's heading. uming the "undesirable" radio transmission hasn't moved, successive readings from different locain should result in vectors that intersect at the
origin of the transmission. In practice, because of limitations on the accuracy of the equipment, is not possible to precisely determine the location of the transmitter from the first set of reaig. Usually, additional sets of readings will be
necessary before the location of the transmitter can be narrowed down sufficiently to allow a grounearch for it.
In order to thwart DF equipment, you must be willing to either limit the length of your transmisns such that the authorities have insufficient time to locate your radio transmissions, or you ms perate from a moving vehicle. Although possible,
neither of these options is particularly attractive, and alternatives do exist.
If you are fortunate enough to live in a location with significant areas of forest nearby, thesen often be ideal locations from which to stage your broadcasts. At nighttime, the authorities aevry unlikely to venture into the woods in order t
o locate a pirate radio station. They are far too vulnerable in such situations and generally willt pursue a suspect unless the odds are overwhelmingly in their favor. Rather, they will cover ayovious means into or out of the woods (such as a
trail) or any roadways in the general vicinity of the broadcasting and search any suspicious indivils or vehicles they discover during the period of time immediately following the broadcast. By aig a few simple precautions, broadcasting from wi
thin a forested area of reasonable size can be the best alternative to mobile operation or 30-minutroadcasts.
It is advisable to first visit the location you intend to broadcast from during the day. Pick acation not too close to any roads or paths and make sure you will be able to find it in the dark Rlatively high points with a line-of-sight to your
listeners is another important thing to look for. Think about where you are going to put your anna. Is there a tree nearby that will provide an ideal placement? Can you climb it at night
without risk of falling? How much coax will you need to reach the antenna from your broadcast locan? Think about several different paths of escape should the need arise. Explore these for a shr istance to ascertain their viability.
After finding a good location to make your broadcasts from, there will be a strong temptation toe that location again and again for future broadcasts. Unless you want to be caught, resist thi eptation. The authorities may have located a site
you have used previously, and could be waiting for you nearby the next time you try to broadcast.lso, when you have finished your broadcast and are packing up, keep in mind that anything you leaebhind will help the authorities in their quest to
find you and bring you to "justice." Assume the authorities will scour the area shortly after you drt so make sure you leave nothing behind for them. If there are smooth surfaces around, don't fore bout fingerprints. Either wear gloves during you
r broadcast, or spray everything you might have touched with a degreaser before leaving.
II. AVOIDING THE AUTHORITIES
(Detection and Evasion)
There are two phases to avoiding capture by the authorities. In the first phase, the goal is totect them well before they have detected you. In the second phase, the goal is to escape withou eng detected or caught. Success in the first phase
will greatly influence the outcome of the second phase.
The authorities rely heavily upon radio for communication. As a result, it pays to purchase a dnt scanner and become familiar with its use and the operating procedures of the authorities. Frqecy lists are available which list the frequencie
s used by law enforcement in your area. In addition, books are available which list federal freque assignments. You should spend time going through such books and making a list of frequencies yo hnk may be used in the event a search for your st
ation were to be conducted. Don't forget to include mutual-aid frequencies in your list as they arften used when different enforcement agencies want to coordinate with one another. You should sedsome time in the general area you will be broadc
asting from listening to the scanner to determine which frequencies on your list are appropriate focanning and prune the remainder from your list. While it is generally better to leave a questioal frequency on your list, irrelevant channels may
reduce the probability you will hear something important on another channel.
Whenever possible, you should take along someone you trust to your broadcast site and have them nd patrol. They should wear dark (black or camouflage) clothing and find a location to stand whr hey have a good view of any obvious routes of app
roach to your broadcast area. A pair of walkie-talkies is ideal for keeping in touch if you will separated by more than a few tens of feet. Keep in mind that your transmissions could be monitord o watch what you say. Don't use names or other i
nformation which could give away your identity or location. If you are using flashlights, purchasome red tail-light tape at an auto parts store and cover the lens with it to reduce your chances f eing seen and to maintain your night vision.
If there are just a couple of obvious routes leading to your broadcast location, you might consi setting up perimeter alarms along those routes. Various party noise-makers are commonly availal t toy stores which make a bang when a string to
which they are attached is pulled.
Using some thin wire, tie one of these noise-makers between a pair of trees through which the ro you want to alarm passes through. Make sure the wire is obscured as much as possible to minimieis chance of detection by any intruders. Make sur
e you set such alarms far enough away to give you enough time to make your escape but close enoughat you will be able to easily hear them.
The key to successfully escaping from the authorities can be summarized as follows: DON'T PANICProper planning is essential. You should have planned several routes of escape beforehand and cniered what to do with your equipment. If time al
lows, you will want to pack it up and take it with you. If you need to escape quickly, hiding it mae your best option. This might be as simple as covering it with something to camouflage it. Pehp you even found a good place to set it up that a
lready takes advantage of natural cover and it is pretty well hidden to begin with. Assuming you aoperating at night, it also helps enormously to wear dark clothing and remove any shiny objects uhas jewelry or watches (leave them at home).
You will likely become aware of the authorities plans for you through one of two means. You wilear about a search on your scanner or you will detect their physical presence. In the former cae ou probably have plenty of time to pack up your
equipment and make a careful escape. You may want to leave incriminating evidence such as your equent hidden somewhere and come back later for it when the heat is off. Plastic garbage bags are da for protecting equipment left in the woods for a
few days. In the latter case, remaining calm and using your head could will make the difference ween being caught with your pants down and just having a close call.
The instinctive reaction to the presence (impending or actual) of the authorities is to flee. Tauthorities know this and if they are even marginally competent will have taken steps to maximiz hir chances of capturing individuals mindlessly r
unning away. Unless they have obviously seen you and are actively pursuing you, you should stop anorce yourself to look around and consider what options are open to you. Approximately how many pol are after you? Are they far enough away that yo
u can move away from them without them seeing or hearing you? Perhaps it would be best to try to rem hidden until they are far enough away that you can more safely risk slipping away?
Unless you are certain that your vehicle has not been detected by the authorities (because it waxtremely well hidden, or parked with a number of other vehicles, for instance), then do not apprahit after your presence has been detected. It is
very likely that the authorities will have discovered it and left someone behind to watch it. By elf, the vehicle is little more than weak circumstantial evidence to connect you with any wrongdig but if you are caught returning to it (especiall
y with equipment), you will probably live to regret it. You should have previously considered othmeans of getting home if there was trouble and follow those plans.
III. DEALING WITH THE AUTHORITIES
(What to do when you get caught with your pants down)
There are at least two different ways of getting caught. The FCC could catch you and send you atice of violation or the police could catch you while broadcasting or while attempting to flee te fter broadcasting. Two entirely different method
s are called for when dealing with each of these.
If you receive a FCC notice of violation, you are probably best off ignoring it. If they start ting serious about trying to collect fines from you, I'd suggest picking up a copy of "How to Fiefr Bankruptcy" by Nolo Press. It details a number
of different strategies for keeping bill-collectors out of your pockets, and if necessary, tells how to file for protection from creditors (it helps if you don't have a lot of obvious assets - ouse or expensive car, for instance). You may al
so wish to discuss your options with an experienced attorney.
If you are apprehended by the police during a broadcast or after an unsuccessful attempt at flee from them, remain calm. They will ask you questions related to the incident for which you havebe apprehended. It is ok to answer questions about
your identity, but do not answer any questions related to any illegal activities you have been inved with.
If you can get away with telling them you don't know the answer to their question(s), do this, orwise answer politely but firmly that you cannot help them. If it isn't obvious (e.g. you have o een read your Miranda rights), ask them if you ar
e under arrest. If not, you are free to go. If so, tell them you would like to speak with your atney before answering any further questions and then KEEP YOUR MOUTH SHUT. They may try to trickyuinto incriminating yourself or providing them wit
h information that will assist them in building a case against you. Do not help them! Make sure and all people that are with you are thoroughly familiar with these procedures as one person slpig up could have devastating results for everyone
involved.
It's probably a good idea to carry the name and phone number of an attorney specializing in criml law with you whenever you are involved in such activities. Attorneys are very useful when it oe to reducing the police's likelihood of violating
your civil rights and they can arrange to have you bailed out promptly as well.
Suggested Equipment
Power:
Motorcycle batteries make ideal power sources. They are available in a number of different size A 12-14AH battery will power a typical 25- 35 watt station for at least two hours before needin obe recharged. These batteries are light enough to
be carried in a backpack along with other equipment for several miles by a single person if necesy.
You will also need to purchase some wire to connect the motorcycle battery with the transmittinguipment. For the power amplifier, especially, make sure you don't use thin wire. It could draw5aperes or more which will not only cause thin wir
es to get hot, but will also result in a substantial voltage drop across the wires as a resulting l of power output. In general, 18-gauge wire should be sufficient for amps up to 25-35 watts.
It is advisable to buy a cheap analog voltmeter that can be clipped onto the battery during a brcast to monitor its condition. Any sudden drop in voltage across the battery indicates it is dicaged, and measures should then be taken to switch
to another power source or end the broadcast. Digital voltmeters are harder to read from a distanor at night and are more expensive.
Transmitting Equipment:
Obviously, you'll need an FM transmitter. A number of kits are available. Any kit that runs off 12 VDC will do. If you want your signal to propagate more than a few miles, you should get a pwramplifier, too. Power outputs around 25-35 watts
are ideal for portable operation with a motorcycle battery as the power source.
Antennas:
Most FM antennas have 300 ohms of impedance. Most FM transmitters and amplifiers expect a load 50 to 75 ohms. It is important to match the load the transmitter/amplifier sees to the antenna noder to get as much signal out as possible and in
order to prevent damage to the transmitter/amplifier. For low-power setups (under 5 watts or so),e way to do this is with a common 75/300 ohm transformer. These are sold at Radio Shack. They aeto a female F-connector, so it would be advisabl
e to get whatever adapter you need to mate your coax to the transformer (most coax has BNC or UHF cectors on it). Running more power through this small transformer will probably saturate it and as the output signal to be distorted.
For higher power setups, you can make a 1/2-wave dipole with two 1/4-wave lengths of wire and socoax. The J-Pole antenna is also relatively easy to make and very portable. See, for example, h RRL Handbook (available at most libraries and man
y bookstores) for instructions on making these and other antennas. It should also be possible to ld a 50 or 75/300 ohm transformer to enable you to use commercial FM antennas with your transmite. Once again, the ARRL Handbook is an ideal source
of information for how to do this.
An SWR meter is an invaluable aid to checking the performance of your FM antenna. They should ays be used anytime you are transmitting with more than a watt or so of power in order to detect a match between the transmitter and the antenna be
fore the transmitter becomes damaged. Once again, Radio Shack sells relatively inexpensive SWR mes that are adequate. Better ones can be obtained at your local amateur radio store.
Make sure you purchase enough coax cable to allow you to place your antenna a reasonable distancrom your transmitting equipment. 50 feet is a good compromise between signal loss and flexibiliyi antenna placement. RG/58 is adequate for such
short runs of cable, but you should consider using RG/8X or RG/8 if you need longer runs of cable.
Audio:
Many radio stations will want the ability to broadcast pre-recorded material from a tape or CD aell as live material from a microphone. A mixer is an essential piece of equipment for such operto. Small, battery powered mixer decks are inexpe
nsive and available from Radio Shack. By connecting them between your microphone, CD player, tape yer, and transmitting equipment you will be able to switch between any of several sources or mixte together.
If you want to use a portable CD player, bear in mind the expected battery life of a fully chargcell, and make sure you bring an extra if you plan a long broadcast. Likewise for a walkman. As,you will need an assortment of patch cables to c
onnect your CD player, walkman, microphone, and mixer together. Once again, Radio Shack is a good rce for pre-made cables of this type.
Miscellaneous:
It is advisable to bring along an FM radio. This will allow you to monitor your transmissions take sure you are getting good modulation and you are tuned to the frequency you want to be.
A piece of foam or other material upon which to place electronic equipment to keep it away from t and rocks is advisable. It is also good for sitting on. Strong, thin cord is handy for tying pyur antenna in a nearby tree or other tall struct
ure.
Head-lamps (head-mounted flashlights) are invaluable for nighttime broadcasting. Purchase some tail-light-repair tape at your local auto supply store and cover the lens with it to turn the ba ed and thus preserve your night vision.
Don't forget to bring along a bottle of water and some snacks to eat during your broadcast.
Security:
Buy yourself a decent scanner. Next, get a copy of local, state, and federal frequency assignme for your area. Program the scanner with the local police, sheriff's department, mutual aid freunies, and anything else you think might be relevan
t. Spend some time monitoring the authorities to become familiar with the operating practices of m.
A partner can be an invaluable aid during a pirate radio broadcast. Make sure he is someone youn trust! While one person operates the radio equipment, the other person can monitor the scanne n watch the perimeter for intruders. Walkie Talk
ies are an ideal way for the DJ to stay in touch with his security.
Further Reading
o Barnett, Richard; Monitor America, SMB publishing, 1992,
ISBN #0-939430-19-3
Contains lists of frequencies used by the local, state, and federal government for the entire Unitetates.
o Hughes, Gene; Police Call, assorted volumes, Hollins Radio Data, 1991
Available at Radio Shack. Various volumes cover local, state, and some federal government frequenc for various regions in the United States.
o ARRL; ARRL Handbook, ARRL, 1992
Available at many bookstores and Amateur Radio stores. Contains a wealth of information about amat radio station operation much of which is applicable to pirate radio as well. Contains informato n constructing transmitters, amplifiers and ante
nnas, among other things.
o Swanson, Chamelin & Territon, Criminal Investigation, Harcort Brace,
1992, ISBN # 0-07-062618-9
If you want to become familiar with police investigative techniques, this is an excellent place to rt. Contains a wealth of information which when applied appropriately will better enable you toaod undesirable run-ins with the authorities when
involved in questionable activities.
How to be a Radio Pirate U.K.
This section tells you exactly how to go ahead setting up your own pirate radio with all theps learned from bitter experience. First of all here's a list of main things you'll need. So yo at to be a radio pirate? Read on...
What you'll need:
A. A group of committed people who get on with each other and have plenty of time and energy.
B. A program, presuming you have something worth saying or playing. You don't even need a sio to start off with. Just borrow someone's stereo and a microphone and start making practicercrdings onto good quality cassette tapes.
C. A Transmitter. Ideally over 10 watt power, but 5 watts is fine for local broadcasts, or when ng an aerial with gain. You can't buy one over the counter in Britain, but here are some lenatives:
I) Buy one from another pirate (beware of rip-offs).
II) Buy one over the counter abroad. In Italy for instance you can get a high quality 50 watt trantter over the counter for ?200. You can buy kits in Belgium, France, Netherlands, USA, etc o then have to smuggle it home.
III) Build your own. A hobbyist can build a low power FM transmitter easily. Try to interest ro hams or dissident engineers. It's almost essential to have at least one person in your group wt ome technical know how.
IV) Get one built to your specification. There are a few electronics engineers about who will build m for a reasonable price.
D. Antenna. You can adapt a design yourself from an antenna handbook (e.g. The 2 Meter AntenBook). Or use one of our ready made designs. Look out for aluminum tubing or struts which mak od building material.
E. Odds and ends. You'll need basic tools (soldering iron, multimeter, SWR meter), a cheap sette deck, probably one or two good car batteries, a roll of coax cable for the aerial, a radi o listen in on, etc. Also start reading Amateur R
adio Handbooks and all relevant writings.
VHF: Pros and Cons
First lets deal with FM (Frequency Modulated) broadcasting, which is probably your choice. Tadvantages of FM are many. The transmitters are small and quite cheap. Reception tends t b either very clear or non-existent. Its excellent
for music and for recording off and can quite easily be adapted to transmit stereo (impossible h AM). A major plus for the pirate is that its easy to hide and transport the gear, aerials ar oparatively small and can be made collapsible.
It's also possible to put in a vehicle, even an bicycle and go mobile, albeit with a smaller d changing reception area. The average 5 to 20 watt transmitter would be in a metal box no iger than 12" by 6" by 3" in size, and weigh no
more than 8 lbs with the rest of the gear (but not including the battery, if you're using one)he aerial is not only shorter but more efficient and of course more practical than the long n ricky procedure for AM aerials. Also low power
FM transmitters ('rigs') can be tuned to slightly different frequencies, on AM you're ck on one, unless you get a new crystal.
The disadvantage is that VHF-FM is essentially a 'line of sight' communication, which means y reception area depends crucially on the height of your aerial above large blocking objects. Thsi no problem if you can get up on a hill, or a t
ower block but it does restrict the choice of broadcasting sites, making you easier to find andap. With local broadcasting you have more choice of sites. In very hilly area, unless you can e p on a mountain, you'd better choose AM, also
if you want to broadcast scattered communities over a wide area. Distance covered with an FM g depends as how much height as on power. A 40 watt rig on a 15 story tower block should cvra 15 miles radius if there are no blocking objec
ts. A 4 watt rig should go 5 miles from the same height but if you build a directional aerial h 'gain' you can multiply that power many times. You don't really need a big expensive an ad to build transmitter. Also don't assume a 10
0 watt rig is ten times as powerful as a 10 watt one, it doesn't work like that.
To sum up, FM broadcasting is the ideal for the guerrilla or community pirate, cheap, mob and adaptable. another advantage is that there's loads of room on the FM broadcasting band, i' literally half empty. On AM its pretty crowde
d, and at night you're likely to be blotted out by continental interference.
The Broadcasting Site (FM)
TOWER BLOCKS
In cities tower blocks have been an ideal answer for good coverage and wide reception and arspecially favored by commercial pirates (who often use a link transmitter from the studio to tetower block so as to go live). A further advant
age is that there are usually electric sockets in the lift or heating rooms on the roof, so yoan just plug in provided your gear is so adjusted, rather than lug car or lorry batteries abou.Tis is 'Stealing Electricity', of course. If
you're caught broadcasting the electricity company could bring this additional charge, though practice we've never heard of it happening. The advantage to sticking in car batteriesi hat you can conceal your rig anywhere on t
he roof, rather than having it right by the plug socket, though in a surprise raid your aerial le will lead them straight to it anyway.
To get onto the roof of a tower block you need a crowbar, or better, a key. The 'Fireman'eys' have to be standard for all blocks, so once you have one you can get onto most roofs easiy
Try asking other pirates, or possibly a friendly caretaker or fireman. Or you can break the d, steal the mortise lock, get keys made up for it, then replace it, such keys may not fit all ros
When on the roof BE CAREFUL (sudden gusts of wind can blow you over the at this height!) always wear soft shoes and keep quiet. Lots of people have been busted simply because the teat below heard them and called the police. Its usef
ul to dress like a repair person, and claim if seen or challenged, to be a lift mechanic. Tmain problem with tower blocks is that, if raided, you can easily be trapped (see how to get awa wth it).
MEDIUM SIZED BUILDINGS
If you're a local station, or have a high power rig or an aerial with gain (or if you're juststing) you don't need to be on a tower block. Any building higher than most others will do, an o can increase your height for instance by mounti
ng your aerial on top of high, well secured scaffold pole (note: there must be a wooden or plic section between the pole and the actual aerial).
The advantage of lower buildings is that you can multiply both the available sites for broadcast. You will have to switch sites as often as possible. Also you will have more escape routes and bl holes' than on a tower block. Unfortunately this
may also mean you have to watch more potential approach routes by the police and DTI, and you need more lookouts if you're planning to save the gear when attacked.
BROADCASTING FROM HILLS
If your town or city has hills this is a good option, the higher the better. You can use a pieof derelict or common land, or at night you can use parks, cemeteries or even allotments. A bte option is if there are hills outside the built
up area, then use a field or wood away from houses. If you use the directional aerial you can co the city just as well. This was done by Andromeda Radio, to good effect, they used to cover moto Manchester from a high hill outside, using
a mere 4 watt transmitter with directional gain aerial. If you can get up into mountainous a you're even better off and can adopt classical guerrilla tactics, often see the enemy coming itances away, and be very difficult to stop.
On a hill within the town or city use good lookouts, escape routes, CB's etc. and have rear 'escape drills'. Best place for aerial is a high, easily climbable tree. If its not too obiu leave it up there and have a spare ready. An a
dded problem with hills is that you normally have to lug at least one car battery about, which terrible if you have to climb fences, ditches etc. at night, something like a pram or shopping toley can help. You can't leave the batteries on
site as they need re-charging for your next broadcast. So mains electric is a big help if you n run a lead from somewhere. Outdoors all your gear must be in waterproof cases, or covered ih a tent or tarp. Tents are good if you can pr
etend to be camping. Take care also of yourself and your group. Hot drinks, food, waterproofsshort shifts for lookouts etc. are good ideas. It gets boring after a few hours. CB's are ecllent, but get ones with earphones if possible
to avoid noise.
If on a hill you can also use ordinary house, flat, squat or derelict, and just set up y aerial as high as practicable on the roof. Its better to get a place, by squatting or if yo'erich, by renting, specially as a broadcast site,
no-one likes to live under constant threat of the police storming in. In practice you may have use someone's house, then don't use it too often. If you must use your own house DON'T leave oe stolen goods, false ID's or other naughties l
ying about. It is possible to run your antenna cable from your house to the aerial on another ro and whip the cable off quick if they come, but this would only work once, and you lose outpu oer with every extra Meter of coax cable going
to your aerial. More of this in the 'How to get away with it' section. NEVER have your studio the broadcast site. They'll confiscate the lot, under the new laws.
OTHER POSSIBLE BROADCASTING SITES
FESTIVALS, especially large free festivals are an excellent and common broadcast site. A smal watt rig will do fine. Set up on a high ground in a tent or vehicle and invite the festival tedees to protect you from possible police attack,
much more unlikely in these circumstances. If possible make a live studio in a tent, caravan truck and get everyone involved. Try to get mentioned in pre-festival publicity, or do your ow, o people will bring radios. This is pirate radi
o at its best.
DEMOS, especially long ones, like blockades for e.g. of Nuclear Stations or War bases, can beually worthwhile. In this context the pirate can be perfect medium for discussion, information n warnings of police movements, as well as for
entertainment and music.
BARRICADED SQUATS OR SQUATTED VENUES are another obvious and much underused site for the guerla pirate, especially during big meetings or gigs, which you can broadcast live from the roof.Ti has been done successfully for instance in Amst
erdam and Berlin.
OCCUPIED FACTORIES or industrial areas during strikes and disputes provide an excellent and of missed opportunity for the more political pirate group, and can provide vital communication o mobilizing, publishing and gaining support. The
re have been many such opportunities in Britain over recent years.
SIT-INS and protest occupations are another good possibility, which we don't think has b tried. Especially occupations of high towers, buildings or pylons for publicity. But in ti situation capture is pretty certain, therefore
a small disposable transmitter would be ideal. A good strategy is for everyone to deny using and to use any following trial for more publicity e.g. on the lines that the army etc. and teplice are already hogging most of the airwaves.
'NO-GO AREAS' are a step up from occupied factories. We know for instance that nationalist pies broadcast from Free Derry and parts of West Belfast when they were 'no-go areas' to the sae Of course there are no true 'no-go areas' in B
ritain, but there are plenty of inner city estates where the police rarely venture, especially the evenings in the riot session, for fear of 'concrete rain' or worse from the roofs. A hg lock on such area could be an excellent site,
especially if you can tip off the local youth to lend a hand. Whenever major rioting begins le areas are suddenly devoid of police, till they can group in numbers and re-take the are.Tis is another opportunity for 'on the ball' loc
al pirates. By monitoring police radio, runners, and phoned in reports such 'uprising radio' coule a brilliant aid
to the fighters on the streets though you would need good security, disposable transmittequick getaway routes, disguised voices etc.
LIBERATED ZONES! (Let us know if you find one!) Practically every guerrilla or Nat. Liberation ement, be they right or left wing, has their own pirate radios, which are often crucial influenc nsuch wars, broadcasting from freed zones or
neighboring countries. But you're not likely to come across this in Britain.
INTERNATIONAL WATERS is of course a favorite site, but out of the question for the small 'do it rself' pirate.
How to set up your gear (FM)
BEFORE YOU GO
Before getting out you had best brief anyone, especially newcomers, on what will or might happen. Taabout getting caught, for instance have good excuses made up for being at or near the site. f you are planning to give false names, for in
stance, you'll need an address where someone will confirm you live, otherwise you might have tbles getting bail if you were arrested. In this case keep your first names the same to avoidbig caught out.
Make out a standard 'check list' of all you need, and go through it before you get out. It's prisingly easy to find yourself on top of a tower block, or climbing some tree, only to discoverta your cassette deck lead is at home five miles aw
ay.
HERE'S A SAMPLE LIST OF THINGS YOU NEED
Transmitter (TX), TX main lead or 2 clip on battery leads (large and well insulated), TX lead tassette deck if not attached, cheap cassette deck plus mains lead or 2 clip ons and 6 volt bike batr, charged up 12 volt car battery if not on mains,
antenna (check you have butterfly bolts if collapsible), the coaxial cable (with plug attached andips or attached to aerial), fused plug board (if on mains), program tapes (rewound to saig position), small FM radio receiver(s) to m
onitor broadcasts, CB's for lookouts, plastic 'gaffer tape', soldering iron and solder in ease broken leads, torch, warm clothes, munches, bus fare.
ON THE WAY
Ideally you need four people, at least two. Carry the gear as inconspicuously as possible, hold alls or plastic bags. The antenna is a problem. If it's a big long one make it collapsibeuing butterfly nuts in assembly. Or try to keep
it somewhere close to the site. On arrival at the site, especially if you've used it before, d an empty-handed scout ahead, to be sure the police and DTI aren't waiting for you and all is la. Check also you're not followed.
SETTING UP
In the case of a tower block you should have been there beforehand and have either a key or a ken lock to get straight onto the roof. Lock the door quietly behind you. If there's two doors ot the roof have access through both. Take your
gear to a lift/heating room and find a plug in wall socket (if on mains). Check it works. Wealoves when handling gear, and clean it regularly with cloth and alcohol. They don't usually bothrwth fingerprint evidence, but they might start
. The antenna must be cleaned regularly anyway for good transmissions. Set up your antenna aigh as possible, if possible on top of an extension pole or length of scaffold pipe. Ofte hre's a pole already, left by earlier pirates.
Attach the antenna securely, with bolts or strong gaffer tape, to a length of wood, then the bottof the wood to the metal pole (if there). The antenna must NOT be touching or blocked by metl he coax cable can be soldered or bolted onto th
e antenna, or attached with strong, rust free car battery clips.
The clips are recommended for fast dismantling and for testing and developing antennas, mark crly which goes where. The coax cable should not be longer than absolutely necessary, you oepower with every extra foot, and should be good
quality and well insulated. Your lookouts should already be on station, with torches or C, one at the foot of the tower (preferably sitting on a car or flat) and one on the roof. Keep lo n quiet and wear soft shoes. (In one court case
Eric Gotts (head of DTI squads) claimed he recognized an Our Radio member from the ground, stories up, at night. The judge accepted his word.)
When the antenna is up securely, lead the coax back and plug or screw in to the back of your tsmitter . Now plug the TX to the cassette deck keeping the two as far as possible apart, fpossible blocked by something solid, like a
wall, to avoid interference. Keep the audio lead well away from the power leads.
Interference between leads can often cause loss of power and/or 'Sprogs' (unwanted signals on theong frequency). You can go so far as to block leads from each other with bricks.
Plug in the cassette deck and the TX to your plug board (or connect to batteries) and sch on. If you have that facility just switch on the exciter stage of the TX first for testing n need to alert Big Brother prematurely. Go on the
other end of the roof with your radio receiver and tune in. Then adjust the modulation oour TX, in relation of other channels, to get the best sound. If this is OK but there's uuual knocking or crackling sounds try moving the
cassette deck further from the TX, or raise it above ground if possible. Try further separatingr screening the power lines from the audio lines.
You may well find that you have sprogs (harmonics or spurious signals) all over the bandheck for this. If so check reception with your lookout 100 yards away, normally such sprog iappear by that distance and you're OK. But if yo
ur signal is still spread all over further away switch off and clear off. Your TX is messed upd needs difficult repair or tuning you can't do on the site. If you find you're interfering wihfre, ambulance or pigs, stop, before they come af
ter you. Most pirates are very careful not to do this.
When all checks are OK, insert your program tape, switch off, and wait for the agreed timo begin. With practice you can easily set it all up and test it in 10 minutes, but it's good oalow a half hour and to be methodical and coo
l. Never, for instance, switch on your TX without the antenna attached, you'll blow it. The p stage of your TX should get quite hot when drawing the power, if not its not workin. ith bigger transmitters you may need also a sma
ll electric fan to cool the heatsinks on the power transistors. Once you're on air its good to and phone friends for reception reports further afield.
Broadcasting.... How to get away with it
KNOW YOUR ENEMY
On a tower block, in London, the DTI squads can tell where you are, within 20 meters, less n 10 minutes after you switch on.
So they can bust you any time. In the case of new pirates the procedure is to monitor yoor a while (in case you're just messing about) before busting you. It could easily be a few mnh before your first attempted bust. If you p
lay anything but straight music they will record and keep all your programs for possible furthuse against you (though voice print's aren't used in court). In other cities they are generallysoer to get after you. In smaller towns they don't
have permanent staff so they have to come specially, depending on your usual broadcasting time, switching your time is a big advantage.
The detection squads are now directed by the Home Office through the Department of Trade anndustry (DTI) and are officially responsible for stamping out 'radio interference'. They hav rcently been recognized and upgraded with fancy
new equipment. Their HQ is at Waterloo House by Waterloo Bridge and they have several otheixed triangulation stations in London, for instant tracking. They use also mobile detection vansadlots of unmarked cars and have a depot in East
London for vehicles and gear. We don't know where they keep their extensive horde of sto transmitters prior to disposal. They also have their own radio frequencies, they used to b ad still may be) using around 88 MHz, just off t
he commercial FM band.
The DTI squads are not supposed to arrest you, so they have to bring the local filth alonn busts, which makes them a lot easier to spot and makes them less flexible, as they often haet wait till the cops have the time free. For larg
e rich commercial pirates the game is to have plenty of transmitters lined up, and not to try tove them if the police and DTI raid. They often use remote links and can often switch on and ofuing timers or radio signals, so they don't have
to go back and change tapes and no one need get caught in the act (but recently the DTI have cked this by raiding the 'live studios' and nicking everyone and everything).
But for small community / political pirates with only one or two transmitters its essential tove the gear if at all possible. At the same time its now always cheaper to lose all the gear tha t get caught and pay the fines. Nowadays even for
the small pirate it may be more advisable to put energy into money raising and mass producing cp transmitters than into trying to save the gear when they're hot on your trail (though youne to guard anyway against the curious and rip-of
fs by other pirates.)
PRECAUTIONS
Don't talk and boast unnecessarily about your sites or studio. Work on a 'need to know' basfrom the start. One method is to keep program makers separate from your broadcasting team, tae an even be delivered to a 'dead letter drop' for
instance. But if you can really trust each other its better if everyone takes a turn at broasting, otherwise the broadcasters can both get pissed off and become a power elite ('I'm no rnsmitting this crap!').
Don't, of course, broadcast your location, real names or addresses. Don't give yourone number either, certainly in Britain, the days of phone-ins and instant access to pirates r numbered. If you're really into phone-ins, get a
phone in a false name at a temporary address or squatted flat (NOT your studio).
Tape the calls and check you're not followed there. For letters use a box address (e.g. Wuppal in Germany) and assume all mail is read, or use a forwarding address. When travelling to ie vary your means of transport.
The raid..... Saving the gear
A.) HIDING IT ON THE SITE
Some pirates have tried building the transmitter into walls, parapets, roof, chimney stacktc. You can conceal it under water tanks, central heating or lift machinery. Better still have thidden in a legal or squatted top floor flat (po
ssibly 2nd to top would do) concealing your coax cable either up the side of the building, by ring a hole in the roof, or by running it up ventilation or 'stink' pipes. Another variatini to have your tape player in a flat, and a lo
ng concealed audio lead to the TX on the roof. The possibilities are endless, and most have betried. On one occasion Our Radio tried the 'dummy transmitter' trick, with it's own dummy ara, leading the hounds to one end of the roof,
while they left by another door. Inside the transmitter box was a can of beer and a 'Booby Pe' note. In all these cases you still need to at least remove your coax cable before the cparive, or of course it'll lead straight to your
TX.
B.) LOOKOUTS
You need two, preferably three, and take it in turns, and if possible also monitor police DTI radio channels. You can use torches or signals from ground to roof. If on CB's turn them vr ow or use headphones, and use codewords, they're
very public.
Watch out for cars and vans with too many aerials, electrical gear in the passenger seat, hing around trying not to look suspicious, police cars passing several times etc. Keep an ey o nearby tower blocks or anywhere they may obser
ve the roof with field glasses. A raid is usually obvious, two or three cars with uniformed poe accompanying them (though piggies may be also in an unmarked car). They usually try and rushi side or a back entrance, so watch out... it's
quite embarrassing to have all your friends nicked, and you still standing out front yawning! Usuy they take the lift (sometimes using a 'fireman's key' to bring it down fast) and often send a fwyoung ones up the stairs.
C.) CAT AND MOUSE
This involves moving and hiding the gear, in flats, stair cupboards, lift shafts, hang out windows, disguised as something else, etc. Normally they have no case if they can't findi, but under the new laws they might try to do y
ou anyway if you're caught. If your lookout system works you have at least 2 minutes warning bef they reach the top of the tower block. You can delay them by switching off the power in the lif om, but if doing this be quite certain you're no
t trapping anyone, which is difficult. You can call the lift immediately, and if you get them fir jam the doors open. You should practice for quick dismantling and packing of the ga n advice. Sometimes its easier to leave the a
ntenna and build a new one. A good simple 'Cat and Mouse' is to run down several flights of stai with the gear, hide it in a good spot (the ideal is the flat of a 'neutral' friend) and tur no a 'normal' citizen. If you're stopped have a
good excuse for being there. Cat and Mouse is a good system to start off with. But remember thehave done it 1000s of times before. When they become determined to bust you you'll need oeand more determined people and new broadcasting
sites to stay ahead. After a certain point they're sure to catch you, as they learn more abouyou, your faces, your habits, your tricks, and as they put more and more men on the case. If yuwant to get away with it its time for a compl
ete change of tactics.
D.) DISAPPEARING
When the DTI are really on your tail one thing you can do is take a weeks rest, then come bawith a different name, style and timing. Of course this messes up your efforts to make a nam fr yourselves and gain a regular audience, but at
least you're still on air, with maybe a few months grace before they start after you again. Also nge your frequency and voices on tape if possible.
E.) SWITCHING
In theory this is a good system, but you need a big team, your own transport, and two or threransmitters (on the exact same wavelength). The idea is this... as the police and DTI close no one location, the signal switches to a second s
ite. Either you're using links, or have copies of the program tapes. The team at the first sitvades the police and sets off a 3rd site and sets up. If they go for the 2nd site you switch tote 3rd site and carry on etc. When combined to Ca
t and Mouse tactics this can make you difficult to stop. The problems are, if you're using towblocks your choices are limited... If you set up say 5 miles away your reception area may be copeely different, and you'll need plenty of dedica
ted people ready to wait night after night to play games with the police... And when they become drmined they will still get you. We know of one South London pirate, who used switching wihaparent success, then one night all 3 of their
transmitters were seized within 15 minutes! Switching would work better when combined and variedith other methods of getting away with it. Particularly if you're doing a local station, wher o don't need so much height, and have lots of mo
re choice of broadcasting sites.
F.) GUERRILLA RADIO
This is one of the main ideas this text is trying to promote. Guerrilla, or Hit and Run radis the war of the flea. First of all you can reduce the risks of getting caught drasticall b broadcasting not a fixed times or a fixed name,
or by doing it only for 1/2 hour periods. The problem of course is that your audience isso random and small. The guerrilla idea is to get together quite a few stations, broadcastingo he same frequency with cheap, mass produced tran
smitters, thus forming one big loose station which listeners would have a good chance of findingn air, while being very difficult for the DTI and police to stop.
BREAK-INS
Break-ins are a higher and riskier form of guerrilla radio, as used in Britain by Radio Arthand Radio Wapping. The idea is to grab your audience by broadcasting on top of a legal station. h sentences are much higher but there's little c
hance of getting caught if your break-ins short, say for five minutes, on top of the news ordvertising of a major station. You're taking advantage of a quality of FM broadcasting thatte stronger signal tends to 'win', blotting out t
he weaker one completely. With a small transmitter you'll only win for a short distance, but eve few hundred yards could cover a whole high density estate. For break-ins strength of signali the main factor, a big powerful transmitter (10
0-200 watts) tuned exactly to the required frequency so you can break in for your message on the m popular channel on prime time. For break-ins all precautions should be doubled, also be sur oclear right away from the area as soon as you've
finished, and don't use the same time or broadcasting site again. It's as simple as that.
Break-ins are also easily possible on TV, but only over the sound. Break-ins are more common iountries where pirates have been repressed, e.g. in Germany or the Eastern Block, and are idea o announcing, demonstrations etc.
There is another and better way of doing break-ins on FM, which may have been used by Radirthur. This is to use the UHF microwave transmitter, beaming your signal at the microwave ihreceiving the signals of a legal station from th
eir studios. Their dish then picks up your signal, and providing you're close enough to be stron than their signal, you get re-broadcast by their main transmitter, thus giving your break-is erfect coverage throughout their reception area
. However, we don't have technical plans to build such tricky UHF transmitters, and it would be qe expensive. Though this type of break-ins is possibly at present. (To stop you fast they'd havet witch off the entire station.) They will probab
ly make it more difficult by using access codes to receiver dishes, as its already done to avoidracy of satellite dishes. NOTE: Don't play around with microwaves, they can be dangerous!
GOING MOBILE
In theory this is an ideal way of getting away with it, but there are quite a few problems. If 're going in a vehicle you can use ordinary car cassette player, but you are better off havig separate 12 volt car battery to power the transm
itter.
One problem is with the aerial. If you use a bigger, more efficient one it will be very oous, one possibility is to have it under a tarpaulin on a roof rack. A bigger problem is hegt unless you can park or drive up and down on a
high hill, your coverage will be badly blocked. And then of course your reception area will vary ically if you're driving any distance. Not much use for gaining or developing an audience. The anadvantage is that you will be much more difficult
to stop.
Going mobile is more practical as a publicity stunt, or possibly for local broadcasts. To a sl extent, having a bigger TX will compensate for lack of height. Going mobile is good o broadcasting at random just for the hell with it
.
Doing break-ins in this way would be great fun in the rush hour traffic.
LINKS, TIMERS, SQUARE WAVES
These aren't for the shoestring pirate, though you can build them cheap if you have the know-. As we said earlier links often prevent you being busted personally, if you can afford to los h gear, and allow you to do live programs. All
it involves is using a receiver instead of a cassette deck, then beaming up your signal from ur studio, or whatever, using a small UHF transmitter (e.g. on 370 MHz) or adapted cordls elephone, or an FM exciter on a different freq
uency (or even an ordinary phone line, though sound quality suffers). You also have to make a smadirectional high gain antenna. If you're using a low power link and a narrow beam its highly ipssible for the DTI to trace you, and it was as
sumed to be safe to link from the studio. But recently studios using links have been raided, a few cases, with every bit of equipment, furniture, record collections etc. seized under h 1984 laws (e.g. a raid on Radio Horizon's studios
in late 1895 when over ?20000 worth of gear was 'stolen' legally).
This may not however mean that the DTI's new gear can detect links. It's just as easy tond your location by gossip, phone taps or just by following you. Links can make you personally ae if they can trace you one you could always use
two, or three, or .... what they don't and can't do is protect your transmitter, its main advant is that it allows you to go live from the studio.
To protect yourself you might as well use a timer to switch the gear on and off remotely. Tim are pretty easy to build, and you can buy kits, but good ones are hard to find 'off the shelf a they can obviously be used to make bombs. A good
one to buy is the plug in variety, used for fooling burglars when you're on holidays, or landlords to deter squatters. For remote switching you can also make sound activated switches, vaa radio link, or 'square wave' switches, via
a phone line. What none of these devices can do however is to turn over the tape, so you still e to go to the site to do this, unless you want to broadcast for less than an hour.
CONFRONTATION
A good trick if you can get away with it. The DTI and police (they normally only bring a few) wide open to attack (the mouse becomes the cat!) when coming to get you. The problem is tha i future you'll have to change your station name
, frequency, even your radio voice and they'll always be on your trail. The good thing is thif pirates start attacking them they have to bring many more police with them, and can only do i hen spare police are available. Also they are a
lways looking over their shoulders, and have to be more careful with their surveillance work. One y to hit back, on tower blocks, is to trap them in the lifts. The lookouts signals up when te're in and you throw the main power switches i
n the lift room. Be careful you don't trap residents as well. Then you take your gear down stairs, beating up any of them you meet on the way, and make off. Their cars are also vulneal, usually they're parked unguarded around the c
orner. If you're going to attack them directly make sure you're well masked and tooled up and e enough skill and numbers to get past them. Go straight for the police officers and disable the bfore they can make their 'officer in distress' c
all (take or smash their radios, or have someone jamming their frequencies). Other direct ways oitting back are attacking the DTI at their bases, attacking their vehicles at the depot, obanng home addresses / phone numbers of chief off
icers and harassing them etc.
Remember they have the entire state apparatus backing them up, any form of direct attack should tefore be anonymous and never spoken of or boasted about later (or before!).
When the lookout signals a raid or anything very suspicious (e.g. a cop car cruising too close often) immediately switch off, dismantle the gear and move it (switch off the TX first, then h ape deck. DON'T rip out the aerial when the TX i
s still switched on!)
Building your pirate station
We're not talking here about commercial pirates, where its just a matter of having good finanl backing, popular DJ's and hit records, plenty of ads, jingles and news replayed from ea stations.
We're talking about the 'do-it-yourself' community or political pirate, starting from squaree, and doing something worthwhile and original. The truth is that most commercial pirates, in hi effort to offend nobody and build towards a
possible license, practice heavy censorship and are often as boring, banal, repetitive, pitalist, sexist, elitist and even anti-democratic as the legal ones, though there are few exetons. Such pirates are obsessed with keeping the
ir technology secret and attacking the competition at every opportunity.
Smaller, non-commercial pirates are in a different situation and can only survive and develoy cooperation, with the eventual aim of breaking the state and commercial monopoly of HrMajesty's' airwaves.
YOURSELF
First thing you need is an interest in sound, and something worth saying or playing. Get a holf a mike and a cassette deck and play around with it. Record yourself, record any and everytig
Listen and record off the radio, off TV, off people's stereos, in the street. Play back your rlts, see where you went wrong, and try again. Note down your results and ideas and discuss them wt others. Read everything you can find about sound
and recording and think about why you want to be a radio pirate. Join the Free The Airwaves campn and read their 'Radio Crimes' bulletins.
THE GROUP
You need to find more people with similar ideas, and not just 'hangers on'. You need to geo know each other well, find out who you can trust, and ditch those you can't. Members shoul b prepared to share in the tasks, risks and
finances equally according to their abilities (in practice this rarely happens).
Hold regular meetings, just keeping in touch can be a problem in big cities. Go for maximum nness so everyone knows what is going on. Beware of the power freaks, ego trippers, party buidr etc. who are sure to turn up sooner or later.
A good point to start is with fund raising, arranging gigs, jumble sales, meetings, sponsored ets or whatever, which can cement your group, attract more people, and advertise your station. o you do it depends a lot on the type of project
you're doing. If for example you're planning a minority language station (and there's milns in Britain who have no radio in their first language) you'll want to advertise widl through ethnic organizations. If you're a 're
volutionary' group planning to claim responsibility for armed actions you won't want to advertiset all. Minority music stations are the most common. But we'd advice you to widen and deepen you rup, or join with others, if you're going to buil
d and maintain the commitment (and cash) to keep a station going. Many music stations get backinrom clubs, and are the platform for the disgustingly egotistical and inane DJ's who work in ths lubs. Such solid backing is a good idea however.
If you're running a station, you'll be hard pushed to fund a raise as well. If you see your statios a part of a wider movement (e.g. anti-war, women, gay, anarchist, animal rights etc.) you sol try to get regular backing from that movement.
Another good trick is to siphon off small amounts of cash regularly from council, charity or udent union funded bodies which your members are involved in. What you need is income, not a o,even ?20 a week would do if regular. If some o
f your members have good jobs they might be able to do it, otherwise you could be tied in wita money making co-op or small business. One example of this is the squatters pirates in Amstera,who can get a small regular income from a fund
raised by a small tax on drink in squatted pubs and cafes.
OPEN ACCESS
Once your group is going well, and you've started to make tapes and get the gear and cash ether, you should think seriously about teaming up with other groups who you broadly agree with o don't disagree). For example at the moment (lat
e 1986) there are dozens of such groups who have failed to get Community Radio licenses ande dying to get their stuff on air, though afraid to 'go pirate' in their present hostile climate
The idea of 'Open Access' is to share a frequency, studios and even transmitting gear to st with, with different groups. The advantages are obvious... more money coming in from more soucs less equipment needed to begin with, a pool
ing of technical abilities, more political clout, more participation, bigger audiences e A good way to approach this idea is by having public meetings, contact Free The Airwaves cmagn etc.
The problems come with coordination, political rivalry, possible infiltration and the sharing oasks. For an Open Access grouping you need regular democratic meetings of all involved (at latmonthly) and insist on full attendance. You need
a few good people who are into organizing it and making it work. Another problem is with broadcang. You should aim for everyone having their own gear and broadcast team as soon as you can, oyu will be more difficult to stop by the police
and DTI. So you should insist on every group producing tapes providing at least two trusted peo regularly both to the broadcast team and to work on the technical and backup side of it (buildn,repairing, purchasing etc.).
Open Access station depend on cooperation, if you have that then all the other advantages cometo play, but you are fighting all the time against our training, in this society, to be competiieand individualist. The ideas of Open Access
radio have been pioneered in this country by stations like Sheffield Peace Radio, Our Radio a Cambridge Community Radio and its worth studying their experience quite closely, as well as te xample of such stations and Federations of pir
ates in other countries. Its often fatal to allow one person, however benevolent they may seem, become a leader or spokesperson for an Open Access grouping. The straight media also love thi ohappen.
LOCAL / "COMMUNITY" PIRATE RADIO
The word 'community' has lost any real meaning, through misuse and over-use (e.g. 'Community Pcing'). The old style communities are thing of the past (if they ever really existed) except o h Soap Operas, as the system breaks us all down
into individual consumers. So if you're talking about 'Community Radio' you should be quite cr what you mean by it, and what the State means by proposing (and then cancelling) such an idea.Wat class, ethnic, interest, political or gender
sections of the people are you aiming your pirate radio at? Or better, creating your pirate ro with? Or are you really working on your own career? Or trying to create 'community' in your w ead?....
Local pirate radio is a more clear idea. There are many advantages to broadcasting locally, e.gore broadcasting sites, harder to get caught, room for more pirates on the broadcast band, chae and easier to built transmitters, closer contac
t and participation of listeners etc. In a big city it's a good idea for your station to base yoelves in one area, whether you're broadcasting locally or city-wide. You need a local bas,ad local backing, financial if possible. If your
station is appealing to one small section of listeners it may not however make sense to do a ll station, because the potential listeners are fewer. A local station should aim at a fail ide section of the population. An Open Access
station would work well on a local basis, as coordination would be easier, and all kinds of inest and minority groups could be persuaded to make programs. On a local basis publicity and uport are much easier to get, as is the
possibility of mobilizing people to defend you when attacked, e.g. a popular station in the middle the large housing estate. Local broadcasting in inner city areas can nevertheless involve hundreso thousands of potential listeners. Most of the
smaller existing pirates are, in effect, local stations, because of the limitations of height ande power of their transmitters, though very few allow any access or see themselves as a local vieand resource.
How to make a studio
Back to square one, you've fooled around with tapes and microphones, but soon you're ng to want your own studio. If you have no cash don't let that stop you! Most of the gear ca b borrowed to start off with. For beginners purpo
se a studio is a small room, a couple of turntables and cassette decks, a microphone, adphones, and a small disco mixer, a plug board, leads, some records and a table to put it al n You'll also need some blank cassette tapes, and
sound effects records if you can (borrow from a record library).
After that it's just practice and patience, knowing and collecting your material, and getting m or better sound gear as you go along.
Having said that there's plenty of tips we can give you. A permanent room is handy. So proof it if you can, cardboard, layers of carpet, egg boxes or Styrofoam are all good. Try topa it out before you start as to have everything w
ithin reach of the operator(s), while having enough room for the interviews and group work. If youild your own control desk you can drill holes and arrange for all the leads to disappear and onunderneath, much less hassle. If you're buying
cassette decks try to get something also suitable for outdoor work. Try it out before buying, . don't get one which leaves a loud click on the recording whenever you lift the pause button.Qaity and editing are better if you record your
final product from mixer onto a reel to reel tape recorder, though it means re-recording o cassettes for broadcasting, and a good cassette deck can give near as good results adi cheaper. If buying a microphone it's worth gett
ing a good directional one suitable for studio and outdoor interviews, and make sure the 'impeda' suits your mixer. A 'cheap' ?50 disco mixer will do the job (you can even mix through some tro units). If you have the cash go for the flashy
new ?150 range with built in graphic equalizer with which you can do wonders. Another tip, keep m leads, din leads and power leads well separate each other and make sure everything is well grone (from the chassis if necessary). If you also ha
ve 'hum' problems with cassette decks try plugging in the power lead the other way round (i.e. whe it goes into deck). Use cheap turntables, not automatics, and buy ones which use cheap catiges, as you'll have to replace them often anyway
. Use good quality cassette tapes however. C120's are best for length of program, but get the besr they'll tear or jam. On the turntables put in your own on-off 'cue' switches, for ease of oeaion. When you've 'cued' a record to where you wa
nt to start, turn it a full turn back, by hand, to avoid slow start up noise. Try and have an Lmeter on the mixer and on the final tape recorder, allow the needle to go just into the red for msc recording, but only half way up for speech reco
rding. For group interviews an omnidirectional mike can be handy, and pay special attention toound recording levels and background noise.
Don't use telephone in the studio. Though the phone is the lifeline of democratic radio, in thresent climate it means you'll be busted and/or have everything in the room recorded by the polie.. You really do need two turntables, and at
least two cassette decks... All these tips, and more you'll pick up as you go along, but it's d to work out standard 'how to use the studio' for newcomers. Pay attention to safety, e.g hve the plugboard (fused) well out of the way,
and don't allow coffee or beer near the gear. Read a book on basic sound studios.
One last tip, lock it up well, especially if it's not in your own home, and barricade and coveny windows. there's one sure thing about accumulating sound gear... sooner or later someone wil nck it!
The program
This is entirely up to yourself. No need to follow any conventions. Some people have to 'master' conventional programming before you can do something different. Other sa i you do that you'll never do anything different.
Again there are some hard learned tips for pirate. It's good to talk with all concerned befortarting, make a list of all the possible material gathered (music, interviews, sound effects, esitems, jokes or whatever) and try to put it int
o some kind of order. A signature tune or jingle isn't such a bad idea, as people recognize throgram by it, often after they've forgotten the name. Repeat the name of your program often, bu nt too often, along with your frequency and broad
cast time.
Put your important items first (e.g. a demo next day, your appeal etc.) as it's always pible you may be busted before the program ends. If you're excepting a bust put all your best mtral first and keep the Word is invalid, but it i
s short. Use first names (false ones) and try to have a friendly, relaxed atmosphere and give evene present a go on the microphone and control desk. While throwing out conventions don't forgt hat we're all conditioned to quick variety and sh
ort attention spans. Long single person interviews are not on, no matter how interesting, buted breaking up, also remember people are continually tuning in (and out) and if doing long piece yu need to 'flash back' the story so far. You
need variety and interaction without sticking in jingles every 30 seconds. Try and make it eresting / enjoyable / entertaining both for you and the audience, otherwise why to bother?...
Style and themes are your department. It's easy on radio to get arrogantly carried away with idea of your own ego, or with 'in' jokes or political hobby horse, watch out for this.
Practice with using the gear, good preparation and research make everything go much smoothly. Bground music and fading music in and out can be very effective if done well. A large studio, tea ras etc. help a lot. The more time you put in the
better the result (usually), you can spend a whole night making a good one hour current affairs prom, for instance.
More than that is hard to say, so much depends on the people, the subject, the projected audien the time of broadcast etc. You should actively go out and seek feedback and opinions from pepeyou know have listened. Probably you won't bee
able to do phone ins and mail is slow and erratic (don't worry if you don't get a big mailbag,w stations or programs really do). It's easy to become cut off and feel like you're talking intoa acuum, or get completely wrong idea of what kind
of people are listening.
Making programs is really not that hard, however bad an inexperienced you are, you can te easily improve on some of the 'aural shit' being pumped out by legal stations over the airwavs 4 hours per day!
Publicity
Publicity is very important, especially when you're starting off your new station. Of course r main publicity is to keep coming back on air, no matter what. But if you're hoping for a minrt audience to tune in specially you need to adver
tise a lot where those people are likely to see or read it. Be warned, there's no real tradit in this country for large scale support for pirates, and people often tend to consume th eia i.e. forget instantly they switch off. It c
ould take you long time to build up the regular, participate audience, and the solid support you d to attract new blood, break even financially etc.
If you're a local station your publicity is obviously a lot easier, and you can poster, gfiti, or even leaflet your entire reception area. If you're a wider station make sure you're awy mentioned in the 'what's on' papers and get arti
cles or interviews into any paper likely to support you. Send out regular press releases tohe local and national press, and try to cultivate contacts among the slimy reptiles (jouraits). Almost any publicity is good, as those peo
ple likely to listen in to you will also likely read behind the bias of Tory press. Oddly, one pe you should certainly seek publicity is on radio, try for instance getting onto phone ins. On ai you are already talking to people who listen to
it! TV, if you can find any way to stunt to get onto it, is the most powerful publicity and you sld certainly court the bastards running the local TV news, this kind of appearance really doe tick in people's minds and start them talking.
..
Strangely enough the media are not overly hostile to pirates, providing you're just an odd, not a direct threat. Many media workers hate the shit they're forced to produce and admire h 'romantic' pirates. You should play on this for
all it's worth, and always try and get your frequency and broadcast times across. They will stimes put you on, as an interesting item. Remember that pirate radio is a 'victimless crime'! If o're mainly a music station you should publicize w
here people listen to that type of music, if you have your own club, of course, you're laugg. Join Free The Airwaves and get publicity in their paper. Write articles for radio pages, and d benefit gigs, public meetings, media stunts,
whatever you can manage.
Choose a catchy, hard hitting name for your station. If you're doing political stuff they'roing to go for you anyway, so you might as well get value for effort!
Remember, if you want to be a participatory station, you'll have to go out and seek feedb. Get out on the street and do interviews whatever you can. Take along your cassette recorde t every type of event, the more different voice
s and views the better.
Building up your pirate station
It's hard to give advice about longer term development, but there's a few things worth sag. First of all it's important to pace yourselves. It's easy to start off with a lot of enthusam then get busted off the air, or just burnt out
with too much work or too few people. However good or different you are you will be very lucky build up a regular audience or mass support overnight. Though your potential number of lseers may be huge you can except response to
be slow. Breaking down passive consumption of the media is not easy. Having your own cl, events, regular demos etc. helps, as do dramatic publicity stunts.
You need to work out what you're aiming at. We say support, participation and a large number listeners is a good aim. But you may just be broadcasting as a way of pressuring for a licne(which is a bit of a sell-out and a pipedream). I
deally you should plan ahead and gradually increase your broadcasting times, while developing alspects of your station, rather than going all out and then collapsing at the first bust. The bes avice then is to operate well within your capabi
lities, and to join up with any other pirates who are not commercial and not racist, sexist fascist. Your longer term aim, as a pirate, should be to reach a situation where you have o uch support (money, volunteers, transmitters,
listener support etc.) that the state just cannot wipe you out at will. The best hope for pira is to swamp the forces of repression by sheer numbers, as happened, at different times, in Blium, the Netherlands, France, Italy, and now, i
t seems, in Spain. This does not imply chaos, but cooperation, federations and sharing of theailable airwaves and times. The swamping the airwaves is NOT going to be caused by the commerca irates, hogging, hiding and mystifying the tech
nology and even sabotaging each other. However if we do manage to start a non-commercial moent of pirates capable of doing this then commercial pirates will jump onto the airwaves ih more power, and try to force us off. This wou
ld be a major problem.
It is a mistake and an excuse to blame the Tories and the new draconian laws for the lack olternative pirates in Britain. The main thing stopping us is the lack of any strong combtv movement (whether it be workers, women, anarchi
st, or whatever) in which to build a big wave of pirates, though there are literally millions of pathetic people about.
Medium wave
ADVANTAGES AND PROBLEMS
At the moment FM broadcasting, with all its advantages, is the favorite for pirates. But itwell worth pointing out that at least 25% of radio receivers in Britain can't even receive FM, soyucan't pick up most pirates on older radios. Anoth
er thing, in some hilly areas FM broadcasts have a very bad coverage area. And a third advantage, ycan cover a very much bigger area on AM, at least potentially. AM can be the best choice for you,epcially if you're in a country area, or in hills
or mountains, or only want to broadcast by day and aren't too worried about sound qualitAM transmitters are also fairly cheap and easy to build, and because you use a crystal there's n roblem with tuning or with 'sprogs' (harmonic
s). Though the antenna is a huge length it's just a roll of wire, and doesn't necessarily have be up high, which gives you a quite different, if still limited, range of possible broadcasigsites. AM works by bouncing radio waves back off
the stratosphere, not by line of sight like FM.
Of course there's lots of other disadvantages, one is sound quality, and stereo is out ohe question, and there's not much free space on the wave band, chiefly because of a host Eurpa stations, which become stronger at night, blotti
ng your relatively weak signal (this is due to atmospheric changes we are told). The TX is alsogger and heavier (about 12" x 8" x 6") and you'll probably need to use car batteries.
One thing I forgot, if you want to reach any of the 50000 prisoners in British jails, youst use AM, FM is still banned in prison, for some typically petty reason.
It is also agreed that you're generally less likely to get busted. In the present repressive clie that's well worth considering.
How to broadcast on AM (540 - 1600 kHz)
YOUR TRANSMITTER
Enough general talk. So you want to broadcast on AM. So here's how to do it. First your transmir. Medium Wave transmitters aren't so hard to build, any good amateur radio buff could do it, n there's people around who will build them (recko
n to spend ?100 to ?150). The technology is tried and tested and our design is as good as any.e TX is valve operated and you use a crystal (which you have to order on the chosen wave length) hch keeps you on frequency without the problems
of FM. So you have to decide from the start which frequency you're going for and stick to it, ory a new crystal. When choosing your frequency remember that it must be divisible by 9... AM frqecies are separated by 9 kHz by international
treaty. If your signal doesn't conform you'll probably have the DTI and police down on you far. If you have problems getting a AM transmitter you may be able to buy a kit or adapt an amaer radio transmitter.
ADAPTING A AM TRANSMITTER
I'm not exactly an expert on this and the following info comes from the US. Apparently you easily buy second hand radio ham transmitters and adapt them. The best to go for is the Vkn Valiant (200 watt) or the Viking Ranger (75 wat
t), both made by Johnson & Co. These ham radios are well built, have excellent audio and mover have built in VFO's (variable frequency oscillators) which make them simple to modify to wor o the top end of the AM band. All you need to do
the RF (radio frequency) circuits is to add capacitance to the 160 meter tuned circuits. And all must do to the audio circuits is to bypass the first pre-amp (assuming you're using a linelvl instead of a mike level). One other thing, yo
u must bypass the speech frequency filter, which is located between the 2nd pre-amp and the driver When buying such a 2nd hand ham transmitter: A) Get one with 160 meter capability. B) Don't p ore than ?100 for one(???). C) Make sure it has plate modulation (look inside and check ther retwo transformers well separated from each othe
r). D) Don't get a 'kit built' one with strange wiring and if possible check the valves before buyi they're rather costly.
SETTING UP YOUR AERIAL (AM)
Security precautions and preparation are the same as for FM. But there the similarity ends. Fo start your total aerial length is 1/4 your wavelength, so if your wavelength was 200 meters, fo istance, your aerial would be 50 meters long! You
use a ordinary thin single strand wire. Buy a roll, keep it on the roll and measure it , meter by meter. Ideally the aerial would point straight up, but that's just not feasible, unesyou hang it out from the side of a tower block o
r a steeple, or suspend it from a balloon (only the balloon blows away). The normal method is 'dogleg' which works just fine. The ideal site is a field, or deserted common land, far aa rom houses, with two tall trees (only 2 if p
ossible, poplars are best) about 30 to 40 meters apart. Now string the 'dogleg' between the treand down to your TX without touching branches or leaves. Sounds impossible? If you have a traie monkey that's just fine. Otherwise try our method
. Practice and patience is necessary.
Bring along with you a catapult, a long reel of 70 lb. strength fishing line, a plenty of leaishing weights (not too heavy for the catapult). Also some small plastic rings (cut out lid o plastic containers work fine).
Tie one end of the fishing line to a lead weight, leaving the line coiled neatly and loosely on iece of bare ground. Then fore the lead weight from the catapult right over the center of a tree G and search for it (don't try this at night). Ti
e on your plastic ring in place of the weight and pass about 30 meter of your aerial wire throughe ring. Now get your mate to pull the other end of the fishing line, if it doesn't get tangled pl it till the ring is about 5 meters from the tree
top. Tie the fishing line securely (to the tree), cut it, and head for the second tree. Repeat e performance, firing right over the tree from the far side. Pull the aerial end through, and hs time tie it to the ring. Pull up as before to
about 5 m from the top and tie the line. Now back to the roll of aerial wire (extended with fishiline as necessary) and start pulling it in till it's suspended without touching the trees! It' ad to get it just right so the aerial reaches yo
ur TX and is tight, adjust fishing line lengths and/or position of TX. Better choose two trees toar apart than too close. When you finally get it all set it's hardly worth taking it down agi fter the broadcast, though you should loosen it
off or it'll snap in the wind. Disguise it if possible. A further problem can be with kids anassers by, disguise your actions, bringing along fishing rods or a kite is a good ploy. One of h est broadcast sites is a clearing in a large wo
od. On Medium Wave remember, you can go right outside the city and still cover it and lots mobesides.
SETTING UP THE GEAR
The transmitter should be on wet ground. If it's dry, wet it. Mud is good stuff. The aerial wishould be taut all the way. Bushes are an advantage, for concealment, but don't let any touch h aerial. Your power supply is a 12 volt car bat
tery. Bring two, well charged up, if you're broadcasting for more than few hours, medium wave s a lots of power. If your TX is on mains (240 VAC) you'll have to get it adapted using a 'rotary nerter', it's not difficult. A lorry battery is t
he real thing, but what a drag to carry! If there's a chance to go on mains, by running a line m somewhere, you should go for it. Otherwise wear old clothes and gloves against acid spills. hn choosing your site balance the need for remot
eness with the problems of moving the gear.
The transmitter must be very well grounded, the earth is an essential part of the aeriaystem. Use a ring of metal stakes (e.g. tent stakes) and file off any rust or dirt for od connections. Attach the stakes securely to the
chassis of your TX, with the thick metal straps or wires held by butterfly nuts or strong cleaattery clips.
So far so good. The cassette player, on the contrary, should be off the ground, on a box oratever. As usual keep the audio lead, battery leads and aerial wire as far apart as possible. h cassette player is normally powered by a 6
volt motor bike battery, with suitable leads. Torch batteries are dear and have a pathetic lifpan.
SWITCHING ON
Connect up your batteries, load up your cassette player with a 'trial tape' and you're ready go.
1) Turn tuning adjuster to the right till the meter gives the lowest reading.
2) Turn 'load' adjuster till meter rises about 50 milliamps.
3) Tune again till it drops about 25 mA.
4) Load up again as above.
5) Carry on procedure till you get a load of about 150 mA on a 20 W transmitter, or 100 mA on a 10 rig. Your last tuning adjustment should produce virtually no dip on the meter needle.
6) Adjust modulation in relation to other channels to get your best sound. Use a radio receiverld at least 50 yards away for testing.
7) If there is crackling, knocking or bad sound, repeat from the beginning. Check that your stakere in well damp ground, that all lines are well separated, that aerial isn't touching trees od receiver further away etc.
If you've done all the above you should be broadcasting loud and clear. If your signal is stiwretched chances are your crystal is burnt out, or something is blown. Then go home.
If all is well, switch off and await the time of your program is due to start. Don't detach ael wire with the TX still turned on.
PACKING UP
When you're finished, switch off immediately. Then disconnect everything and pack into hoalls or large plastic bag. Be especially careful carrying the TX with it's delicate valves. o should have several sites, and switch as often
as you can. Don't re-use a site after an attempted bust. If you have a good dry safe stash and coming back best leave your transmitter, cassette deck and leads there, and just take the ateries back for recharging. Such a stash shoul
d be in cover, be quite sure a hidden watcher or bud with binoculars couldn't spot you stashing gear. It's likely that the DTI will send in men to sneak up and watch you, prior to planningabst, so be careful, even when not on air, don't
relax till safely home.
WHEN ON AIR, PRECAUTIONS (AM)
Read the FM chapter 'How to get away with it'. A lot of those precautions also apply.
At a AM site your chances should be much better, you need on person just to stay near the in case of kids, passers by etc. and to grab or hide it fast when they get the danger signal O many sites you can work out lookout points to
give plenty of warning. However you might as well abandon the batteries, and certainly t aerial, if you have to run far. If you have transport or good escape routes you can tryacean getaway, but safer method is to hide the gea
r well (not too close to the aerial if it's left up) and beat it. We favor bunkers, holes pre-dug lined with waterproofs, under rocks, with heavy lids covered with earth and bushes. In theor hy could find these with dogs or metal detectors
, but we've never heard of them succeeding or even trying (you could always bury bits of metal aover the place).
The possibilities are unlimited, if you're on the ball there's no reason they should get the ge.. and without that they have a lousy case against you.
Busts.... If all goes wrong
You're nicked. What you say to them depends on the circumstances. If they haven't got you, deny point blank, give them your cover story and a verifiable address, and stick to your story no matrwhat. The problem with this is if they have nicke
d others and they give different stories, a different name for you etc. Best discuss all this befornd. If caught on the hop, best say you don't know any of the others. You're caught in the act or wt he gear. Give them a verifiable name and addre
ss and refuse to discuss the matter further. No matter what. People have managed to get off in thpast, even with the gear in their hands, but under the new laws this is unlikely.
Although they can arrest and charge you, illegal broadcasting is still normally treated as a 'sons offense', which means they question you, let you go (eventually), then summons you by lettrt appear in court. This opens possibilities of ge
tting away with it - you may be able to snow them with a false name etc. (though they can now hoyou on suspicion of doing this for three days). They will normally 'ask to accompany to the stato' or if they've raided your flat may interrogate y
ou there and then. If you refuse to go to the station they will arrest you (for obstruction, inting words, suspicion of stealing electricity etc.) and take you there, where you can be interiwd by the police and DTI. The 'pretext charge'
is often dropped later. When interviewed on the station it's better really to refuse to say anytg, especially if there are several of you, cover stories usually fall apart under long and dtied questioning. However silence usually means t
hey will hold you longer. If they get you to the station they are pretty certain to photographnd fingerprint you. You can't refuse under the Police Bill.
When nicked your best bet is to remain calm. Demand to ring your solicitor. Don't panic, it's the end of the world. Smile at the bastards. Have a good time in the cell -you've done your et
Fighting your case
It's usually months before your summons arrives, if they decide they have a case. Get legald if at all possible, and a good solicitor who knows the, by now, pretty complex legal situain
Plead NOT GUILTY, but beware if you have money, they may award costs against you if you loseet your Bust Fund together, with gigs, jumble, radio appeals, donations all round etc. It's goo ocampaign about your bust on the air if your
station is still going. Most commercial (read conservative) pirates don't do this, carrying theiid for respectability so far as to ignore their own best weapon. Make sure the address you gav hn arrested is 'clean', they could possibly r
aid you to look for further evidence. If you're a political station watch out for suspicioureak-ins where nothing is stolen, the Branch often do this. Get your story straight, get winses to write out their statements together, m
ake copies and give them to your solicitor.
Don't trust your solicitor too far, they sometimes say 'plead guilty' just to save themsel trouble, if he/she starts getting cold feet get yourself a new one (they don't like this at all u it can be done). Get your solicitor to ask fo
r copies of the prosecutions witness statements in advance of the case and make sure you s them. In court dress neatly and be polite to the bastard (magistrate) and the filth. Have a go hard luck' story for your solicitor to tell, i
t's always good to say you're just getting married, starting a new job etc., but don't say you e money or the fines will be bumped up higher. If you're going to 'bend the truth' a little dnt tell your solicitor you're doing it, and be s
ure friends watching in court don't start laughing!
The DTI and police will lie anyway, more likely than not, get your witnesses to focus on these l and your solicitor to cross question them closely, especially any police witnesses, who are oestupid and inexperienced in this kind of case
.
Demonstrations outside the court are good publicity and can intimidate the magistrate if enough, but don't always help your case (e.g. if you're pleading 'dumb bystander' how come all hs people are so concerned about you?). If you wan
t press, send out Press Releases at least a week in advance, so the hacks can put it in thediaries, and phone sound with reminders the day before. Your fine should be paid by the Bust Fun fat all possible. If not, extra costs should be
divided up among everyone in the station (always plead poverty and ask for time to pay). When you'been busted once you shouldn't, ideally, work on the broadcasting end again, though you could stl o lookout, backup, monitoring etc., as second
offenders normally get the maximum fine.
If you win the case, as quite often happens, have a good party! If you win there is also some sibility, in theory of claiming the gear back, though this is much less likely under the new law. Ask your solicitor about it, and there's a chance get someone else, with some kind of recpt to apply for it, saying they'd bought it before the bust.
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Radio Crimes is the name of the FTA bulletin, and will carry full technical updates on these desig and much more. To join FTA and receive the bulletin send ?2 (for organizations: ?10) to h ddress above.
The KZAR Story
If you can't afford the outrageous price-tag required to start a licensed radio station, if you'tired of commercial alternative stations that play Nirvana ad nauseam, don't fret.
It's easy for you to take matters into your own hands. Try this recipe for making your own radioves: 1) Know the right electronics equipment dealers in town, they'll hook you up with parts to aea transmitter (about $50 per 5 watts: you'll pro
bably want at least 20 watts); 2) Buy an antenna, a microphone, maybe a filter, a mixer and a CD plr; 3) Round up your friends, vote on a format, choose a frequency, boost your power, then snub yu ose at the Federal Communications Commission (FC
C). You owe it to yourself. After all, you broke the rules -- or, more exactly, the law.
This rebellious, and, when you add music, romantic stealing of the airwaves was played out by Chrian Slater in 1990's "Pump Up the Volume." In Salt Lake City recently, it's become radio realit nSaturday nights at 11:30, sans the "young - man -
4~ with - something - to - say" attitude of the Hollywood movie.
Promoting itself by way of flyers in Salt Lake City coffee shops, KZAR, or Zion Alternative Radiorides itself as a breed apart from "those commercial money-grubbing giants." That explains its maly" output power of 35 watts.
"After extensive research and help from listeners," so says the station's voice mail, four areas e scouted for best reception. Guaranteeing that Salt Lake's upper-class won't be deprived of pirt adio, KZAR comes in best in the Olympus Cove and
East Benches area.
The other three are the Murray Area, the West Valley Area, and, naturally, the higher North Benc and Capitol Area. If you want to listen to KZAR in domestic comfort, you've got to wire up you eeiver and string an antenna out the window. Oth
erwise, KZAR is radio for the road.
Nestled between KBYU (89.1) and KUER (90.1), KZAR seats its throne at 89.5 FM. Station manager Dri Baughman (a pseudonym) chose a lower band because, reportedly, the FCC is more lenient on pirae(nlicensed) broadcasters using the educational fr
equencies, as opposed to the higher frequencies of commercial radio. Pirate radio is not a violatithe FCC takes lightly. "They [pirate stations] are illegal. The FCC has sole jurisdiction over araes and broadcast signals for the public domain,"
said Tom Hora, public affairs officer for FCC's eastern California field office, which regulates U airwaves.
Recently, in California operators for the station Free Radio Berkeley were apprehended and fined ,000. Federal regulations governing radio stem from the Communication Act of 1934, which ruled ta he airwaves, unlike print media, are public, not
private property. The United States isn't alone, as Italy is the only country that doesn't crack n on free radio operators. Hora makes the point that pirate broadcasters interfere with other sains' legitimate use, cost consumers money, and eve
n endanger lives.
"What if a commercial airline can't reach the control tower
because of a pirate frequency? It has to turn around and try again.
That costs the airline fuel, which is passed on to consumers," Hora says. "What if the pirate fuency jams communication between police and firemen and they can't respond to an emergency?" he aswith a wild voice.
The FCC isn't even the least bit curious about why people broadcast illegally. Pirates are just ain in the neck. "Why do people shoplift? Why do people do things they shouldn't do? It's impsile to determine," says FCC engineer Bill Zears.
Nationwide, the motives are as varied as the U.S. population.
Until recently, an Illinois man used his homemade station to broadcast jazz and black nationalist n and opinions on such topics as police brutality. In Michigan, one couple used a transmitter tobodcast anti-gay propaganda, and, of course, Neo-n
azis get in on the act.
Overseas, the aim is more about music. English pirate station Caroline even led directly to the ctry's first popular music station, BBC's Radio 1.
Baughman's motives are personal and political, not overtly
malicious or sociopathic. His first introduction to the idea was through the computer network, Intet. Since then, he's been broadcasting on-and-off since late June. Understandably, Baughman declndan in-person interview and photos.
"To be honest, I like to play DJ. It's a small movement and I wanted to be part of it. I'm pretmuch anti-government anyway," he says. Baughman and his group of "sandbox" radio enthusiasts, a eputs it, have enough power to broadcast over the
entire valley, but need a higher antenna, an item that's next in line for purchase.
The listening menu is a loose "alternative" format that, disappointingly, often veers on the commial, especially on Chloe Devereaux's "Blood, Death, and Roses" segment of the broadcast. The Th,Nw Order and INXS are probably the last bands you
'd expect to hear on a pirate station. They're easy pickings on commercial radio, but KZAR is prouo bring them to you. Broadcasting into 4 a.m., however, the mix became more subversive: Meat BetMnifesto, Sex Gang Children, and techno-rave beat
s.
The best feature of KZAR is its news segment, chock full of enough conspiracy theories to make Olr Stone look like an amateur. News item: "The U.S. Government is using closed-captioned decodersisalled in TV sets to obtain classified informatio
n about American homes."
Pirate radio's national agenda reaches far above mere music, though. According to Baughman, its e goal is to obtain FCC rights for micro-broadcasting licenses, more reasonable licensing costs,adget FCC bureaucrats to tune in to the positive e
ffects of small stations serving the community.
That will be a long time coming. Until then, Baughman and crew will turn on the transmitter everaturday night and claim a small piece of turf among Salt Lake City's 40-odd radio stations.
Other stations have yet to complain to the FCC about any signal interference.
"I really don't give it [pirate radio] much legal thought,"
Baughman says. "When something does happen and I do get caught, I'll worry about it then."
The Ramsey FM-10 micro-transmitter.
Here is a compilation of information about the Ramsey FM-10, and other BA1404 Stereo FM broadcass. Some of the modifications may make your BA1404 based broadcaster illegal to use on the open iwves in the US and Canada. Also it has been brou
ght up that the stock Ramsey FM-10 kit may exceed FCC power limits when used with a proper antenna.
Recommended Test Equipment
--------------------------
An SWR/Power meter is a giant help, a CB to 2 meter one will suffice. Power readings will not becurate, but can be useful for peaking. The most important part is the SWR meter, this is very imotnt when making an antenna.
A note on power meters: The above power meters are recommended because they are inexpensive and t people that are interested in hacking a FM-10 have very limited funds. These are by no means cuate, but they will give you some idea what is goi
ng on. If you can spend the money you can get an accurate power meter that is designed for this b, but the cost is 10-15 times more.
A 50 ohm non inductive load is also very helpful, for low power applications a 50 ohm 1/4 or 1/2tt carbon resistor works well. This can be used to tune up your kit and amp without interferingwt anyone. Also note that you can run as much pow
er you want, legally, as long is it doesn't radiate.
A VOM is also very helpful. It is worth the extra bucks and buy one with a frequency counter (iou shop around, about $60-$70). Buy the one that covers audio to 20 MHz (or more). If you are eius about electronics you need one of these!
Dummy load
----------
Dummy loads are great for testing, without radiating a signal. In fact you can run as much powes you want into one of these things legally!
Basically you want to create a non-inductive 50 ohm load. This can be done with regular carbon istors, or by buying pre built Amateur or CB radio loads. For low power ( <.5 watt ) an etherne eminator works well (check temperature when using
if it gets very hot lower input power, if it is still cool you may be able to go up to .75 watt.) t CB loads use a 2 watt carbon 50 ohm resistor.
You can build your own, as wimpy or as sturdily as you want by running resistors in parallel to ate 50 ohms. i.e., 2 100 ohm 1/4 watt resistors will create a 1/2 watt 50 ohm load...
Do not use 50 ohm wire wound resistors, they are not 50 ohms at radio frequencies.
Ramsey's Address
----------------
If your looking to purchase a FM-10 kit and can't find one locally try :
Ramsey Electronics, Inc.
793 Canning Parkway
Victor, New York 14564
Phone (716) 924-4560
FAX (716) 924-4555
Ramsey FM-10 70 mw output amplifier
----------------------------------
Provides almost 9 db gain to bring the output power of the Ramsey FM-10 Stereo transmitter from w to 70 mw Not the best design, but all parts can be found at Radio Shack!
+12 v
|
/
\ R1 *220 ohms(1/2 watt)
/
\
R2 9k | C2
-/\/\/\/-----------||-----> output
| /
| /
| | /
C1 | |/ <----------MPS2222A (276-2009)
in --||------|\ -or- 2N4401
^ | -> --
| |
| GND
currently on board
* you can also use 2 440 ohm 1/4 watt resistors run in parallel
This thing can be built right on the underside of the FM-10 kit, C1 is the cap that currently goto the RCA ant jack, the 9k and the 220 ohm resistor have to be bought, note that if you cannot id220 ohms you can make one by using 2 440 ohm res
istors in parallel, and that a 10k will work in place of the 9k but yields poorer performance (-5%) The MPS2222A is from Radio Shack part number 276-2009, use this part! If you substitute it for aN222A you will get only half the gain. Be very careful to get the leads in the correct orientato!
The 2N4401 can be used in place of the MPS2222A with a little better performance, about 5 mw mor The 2N4401 can be found at Radio Shack, too.
C2 is of the same value of C1, this is the one that goes to the on board antenna pad.
Important, the value for R1 that seems to be optimal is 220 ohms, but it is very close to the saoint, If the amp seems noisy (interferes with the TV etc.) back this value off to 240 ohms. If o ower this value below 205 ohms the power meter ma
y read higher power but this will not be true, the transistor will be spewing all kinds of junk anhe power meter will mistake this for higher output (in reality the signal we want will drop
considerably.)
After this modification the, effective range with a good antenna should be a little over double.
Ramsey PA-1 2-meter to 3-meter conversion mod
---------------------------------------------
The Ramsey 2-meter amp (PA-1) can be converted for use on the FM broadcast band. The inductors and L2 need to be changed to the following:
L1 - Should be replaced with a 1-turn 1/4" diameter coil, Identical to the stock L2 shown in thA-1 manual.
L2 - Should be replaced with a 2 turn 1/4" diameter coil, one more turn than the above coil.
Tune up should be the same as in the PA-1 Manual. Note that a FM-10 kit cannot be used to drive A-1 kit alone. The FM-10 kit doesn't put out enough power to turn on the PA-1 kit running classc So you have two options. One, you can do the "bi
ased on" (newer kits may call this class-b) modification shown in the PA-1 manual. Doing this youn drive the PA-1 with a stock FM-10, yielding about 200-300mw of output power. Or two, you can rv the PA-1 with the output of the 70 mw amp shown
above and get close to a watt of output power.
It should be noted here that running the PA-1 "biased on" (or class-b) produces a much cleaner out signal than running the PA-1 class-c. Also that you can run the PA-1 "biased on" while drivigi with the 70 mw amp, but you will show slightly l
ess gain than in class-c.
ANTENNAS
--------
Antenna are the most important thing that you can do for extended range. A 1/4 wave ground placan be built using a UHF connector and 5 lengths of copper plated brazing rod (found at the loca eding shop). Works great and only cost $3 dollars
to make.
Remember good antenna will improve you range much further than a good amp into a bad antenna. Shis should be your 1st project to increase your range.
Use the formulas out of your FM-10 manual 234/freq=length of rod.
Example : 234/88Mhz = 2.66 feet * 12 in/feet = 31.9" -or-
234/108Mhz= 2.17 feet * 12 in/feet = 26"
Insert the 4 ground plane rods in the 4 holes of the UHF connector, stick them through about 1/4 h and solder. Solder the radiator in the top of the UHF connector (you may have to grind it a btt fit.) Then bend the ground plane rods to a 45
degree angle to the radiator. This makes a very effective antenna, just connect with a 50 ohm CB ce to your amplified Ramsey, stick the antenna in a tree or in another high place and you should ae1 miles of solid coverage (when using the above
amp.).
If you have an SWR meter you can cut the rods a little longer and start clipping the ends off a tle until you get the best SWR reading.
Be careful when you bend the brazing rod, don't break the connector. Grab the rod right below thonnector with a pair of vice-grips and bend the brazing rod at that point.
Try not to have anything metal near the radiator, this will effect the radiation pattern. The ration pattern should look a lot like a deformed doughnut surrounding the radiator
On The Road
-----------
Old magnet mount CB antennas can make great mobile antennas, simply take the base load out of thand cut the radiator to 1/4 wave length.
If you need a longer radiator than the one that comes with the antenna use the above mentioned bing rod.
This antenna works great! It is better than a dipole and you can drive to a high, optimal locat for your broadcasts (and you can see the vans coming for miles. Also with this setup you needvr little coax cable. Line loss using RG-58u can b
e killer at 100MHz. You could also try a 5/8 wave length antenna, this would give you 2+db gain, olmost 2 times power gain on transmit.
Filter design for FM Radio Transmitters.
----------------------------------------
It is very important to have a clean signal. 99% of all people who get busted for illegal transming is that the neighbors complain about interference. Most of this interference is caused by hamncs. Filters cut down these spurs. Don't draw att
ention to yourself, be clean, and use a filter.
When you amplify a signal, you get unwanted by-products these are called harmonics. The show up multiples of your starting frequency. For example, if you amplify a 50MHz signal you may get suius signals on 100MHz, 150MHz, 200MHz, 250MHz...
If you interfere with your neighbors TV, the local fire department, or anyone else, you are just ang for trouble. If you are only on the FM Band with a clean signal, you will hardly be noticed.
Filter Designs
--------------
Filter Design: 7 element Chebyshev
Designed for 88.1 Mhz. First harmonic is 176.2 Mhz
Fc 3db 20db 40db
85.8MHz 95.9MHz 116MHz 148MHz
.132uh .150uh .132uh
-----()()()-----()()()-----()()()-----
| | | |
<-50ohm - 33pF - 68pF - 68pF - 33pF 50ohm->
- - - -
| | | |
--------------------------------------
|
---
-
Lowering the 33pF caps to 30pF and the 68pF caps to 62pF would make this filter suitable for hig frequencies like 100MHz.
Filter Design: 5 element Chebyshev
Fc 3db 20db 40db
81.8MHz 105MHz 147MHz 222MHz
.128uh .128uh
-----()()()-----()()()-----
| | |
<-50ohm - 30pF - 62pF - 30pF 50ohm->
- - -
| | |
---------------------------
|
---
-
The tough part in the above is winding the coils. 3t of #12 wire 1/2" diameter should be about .1h. 4t is .17 uh. (but ugh, #12 wire is big stuff). You could just use molded inductors, these wokwll. Try to use fixed value caps, or fixed value
with small 5pF trimmers. The latter works well when you have a spectrum analyzer available for tug the filters.
Very simple filter.
-------------------
.15uH
from TX >------()()()------> to antenna
| |
- c1 - c2
- -
| |
--- ---
- -
88MHz 102MHz 107MHz
c1 62pF 54pF 50pF
c2 62pF 54pF 50pF
It won't attenuate the harmonics as much as the other two designs but it uses standard off the sf parts. The inductor is one of those molded units that looks like a resistor so you can make ti ery small. You may stack these things to make a
better filter. Each stage will knock the 2nd harmonic down about 15db.
Use the above cap values depending on which frequency range you want to operate at. i.e.. if youn 87-90 use the 88MHz values, 90-103 use 102MHz values, and above that use 107MHz values. Try oue fixed value parts!
[Also of interest is that the FM-10 puts out about 8-9mw and the 2nd harmonic is -25db off the famental (frequency we are broadcasting on). The FM-4 Kit by Ramsey puts out 130mw and the 2nd hroic is only -12db off the fundamental, which means
the 2nd harmonic of the FM-4 is about as powerful as the FM-10. db is log10, i.e. 3db is 2 timesb is 4 times...]
FM-10 Myths
-----------
There have been several myths about the FM-10 kit, the most prevalent are :
1) The FM-10 puts out 100mw of power. This is not true, or at least not true for common Ramsey F0's. They put out between
8 and 12mw when driven with a 12 volt supply. (Note: there has been several revisions of the FM-10t is possible that the original version put out more power, but that is highly unlikely since itwud require another amplifier stage.) Also the FM-1
0 is the only low cost kit with an amplifier stage. Most others have power outputs in the fractiof a mw area.
2) The FM-10's output can be cranked up by reducing the value of R9. This, like the above is notue. R9 and R10 are optimized for maximum output and greatest harmonic suppression at 12 volts. Tee are much better ways of getting more output po
wer than to mess with this output stage. Lowering the value of R9 will most likely degrade the FM-s performance and cause lots of interference.
FM-10 Improvements
--------------------
Stereo Pilot Mod
----------------
One of the first problems experienced with the FM-10 is difficulty in getting the stereo pilot tperate correctly. One solution is to replace C7 and C8 with a 38KHz crystal, this works the betad is recommended. If you cannot find a 38KHz cr
ystal, you can make your life a whole lot easier with a couple part changes. As indicated on the Rey schematic, about 110pF is necessary to tune the oscillator. The components supplied to achieetis are a small fixed value capacitor (C7) and a
slightly larger value trimmer (C8). Since proper setting of the trimmer occurs within a very small ndow' (about 5% of the trimmers range), it can bet difficult or impossible to adjust the pilot t 9Hz and have it stay put. This can be cured by i
ncreasing the value of c7 to 100pF and replacing c8 with a 6-50pF trimmer (Radio Shack #272-1340); -30pF trimmer will do the trick. The RS trimmer will not fit the holes in the pc board; one neest cut the leads off a spare resistor and solder t
hem to the legs of the trimmer (just use bits of wire) to mount it on the component side of the boar On a 2nd note: Replace c7 with a 68pF cap and it is much easier to tune a rock solid 19KHz at thest point.
NOTE: Ramsey now includes a crystal with all FM-10 kits. Owners of the old kits can contact Ramsey an upgrade kit, which includes a crystal.
Crystal Mod
-----------
old set up new setup
c8 c1 xtl where c1=10pF and xtl=38KHz
|-||-| |-||-|\|-|
| c7 | | | v8=var cap
|-||-| | | c7=cap
| | | |
Remove C7 and C8, replace with 38KHz crystal and 10pF cap. Note that the 10pF cap and the crystare running series and the old cap setup is running in parallel.
Note: there have been good and bad reports on using the Epson crystal from digi-key. People saye crystal is quite delicate, and in at least one case the experimenter destroyed the crystal.
In one of the positive cases, C1's 10pF cap was replaced by 2 22pF caps run in parallel, this yied a rock solid stereo.
Treble Boost Mod
----------------
Treble boost (pre-emphasis) improvement. The FM-10 appears to have been designed by someone oute the United States since it operates at the European audio standard of 50 microseconds. Receivesi the US are set up for 75 microsecond de-emphasis
. R3 and R6 determine the time constant for the pre-emphasis curve. Replacing them with 75K ohm retors (standard value 68K ohm is close enough) will result in improved audio response.
A much better pre-emphasis/input circuit is shown in the July 1992 issue of "Radio Electronics".ot only do they use 75K ohm resistors in there pre-emphasis, but they filter stray RF signals byisrting a .001 cap between pin 1 (of the BA1404) an
d ground, and pin 18 and ground.
It has been noted that the above mod may actually cause distortion on cheaper stereo receivers, ce they were mass produced for the world market, they were designed for the European audio standr,which Japan and other Asian nations use too. Tr
y it out, let me know what works for you.
Anti-Drift Mod
--------------
There has been quite a bit of discussion on the FM-10's frequency stability. Complaints that digl receivers cannot lock onto the FM-10's signal for any great length of time. The below mod has enused with good results using a N750 negative tem
perature compensated disc, but Mylar or Polystyrene caps are even better.
The FM-10 was designed to be inexpensive and cost-saving measures with components are inevitableisc ceramic capacitors are less expensive than silver-mica caps, and also much less stable. Siml eplace c16 with a silver-mica, tantalum or negat
ive temperature compensated disc (say anywhere from N150 to N750) cap of the same value.
Sources
-------
The following is a list of sources for items used for modifications, replacement parts, or otherts and equipment used in FM radio transmitting:
BA1404s and other FM Broadcaster kits can be found at :
D.C. Electronics
Phone: 1-800-467-7736 & 1-800-423-0070
Fax:1-602-994-1707
They sell BA1404s for $2 a piece, seems to be the best deal going. Also they Sell 38KHz crystalsr $5.99, which is also a fair deal, the crystals are tiny ones like the digi-key ones, but are adferent brand and work without problems.
38KHz Crystals can be obtained by calling :
Digi-Key at 1-800-DIGI-KEY.
38.000 KHz by Epson America, Digi-Key part No. is SE3314
(see notes on crystal mod on using this crystal) Note that
this is a cylinder type crystal and is delicate. You are probably better off getting the 38KHz cryst from D.C. Electronics.)
Panaxis Productions makes some very high quality FM transmitters. The last word in Transmittingons of kits.
Panaxis Productions
PO Box 130
Paradise, CA 95967-0130.
(916)534-0417
Catalogs are $2, well worth it, a must have item.
A little taste of there catalog :
MMC1 Macromod Compander for 2:1 compression
Plans $12, PCB $18, P+P 26.50, Full kit $87
SG High performance stereo generator
Plans $15, PCB $13.5, P+P 26.50, Full kit $105
FME PLL FM exciter
Plans $17.5, PCB $15, P+P 24.50, Full kit $129
More expensive than a FM-10 but much higher performance.
A company called Progressive Concepts sells plans for a 88MHz to 108MHz amp. The power curves s that 12mw in will yield 2.5 watts, but can be driven harder for up to 12 watts.
Plans only in U.S., $16 (a bit spendy, ouch!)
Progressive Concepts
1313 N. Grand Ave. #291
Walnut, CA. 91789
If your looking to purchase a FM-10 kit (or a PA-1 kit) and can't find one locally try :
Ramsey Electronics, Inc.
793 Canning Parkway
Victor, New York 14564
Phone (716) 924-4560
FAX (716) 924-4555
Should be $29
The makers of the infamous BA1404 :
Rohm Corporation
Rohm Electronics Division
3034 Owen DR
Jackson Business Park
Antioch, TN 37013
PH: (615)-641-2020 (ask for someone who deals with the BA1404)
FAX: (615)-641-2022
Also they have:
PO Box 1399
Antioch, TN 37011-1399
Miscellaneous:
The 2SC2570 is supposedly replaceable with an ECG10. The MRF901 can also be used as a replaceme although it is tough to mount. Try mounting it on the bottom of the pc board and connecting thewi antenna pad to ground plane. MPS901s seem to re
place the 2SC2570 directly. They use the same case, but check the pin-outs. MPS918s work well also The MRF239 can be used as direct replacement for the Ramsey 2 meter PA-1 kit. Cost is around $1
Newark also has the 38 KHz crystals for $2.90
A TV Transmitter
For some time now it has been possible to construct a clandestine television station, which you coperate from your Telecommando Lair, or modify or Mobile Media Guerrilla campaigns.
This device has been named the Snow Box, due to its cool nature, and the snow seen on blank teleion channels waiting to be commandeered.
To put together a TV station you will need this stuff:
1) A VCR or Camcorder with video or RF outputs
2) A Ham Radio 6-meter Band Linear amplifier
This boosts the RF signal from the VCR for broadcasting. The Linear Amp should have a bandwidth of 6z for best results. A cable television RF distribution amplifier may also be used.
3) Coaxial cable with UHF connectors
(Connects the Linear Amp to the Antenna)
4) A cable-TV patch cable with an F-connector and a UHF connector. (To connect the RF signal to the ear Amp) (F-connectors are the small ones used with cable TV) (UHF connectors are the large ones sdfor Ham Radio)
If your VCR does not have RF outputs:
An external RF modulator (converts video to channel 3,6,12 etc.), a cable with RCA connectors (aandard stereo cord is ok)
5) A 6-meter Ham radio antenna.
If you do not have a pre-made 6-meter antenna:
About 20 feet of strong wire
3 ceramic antenna insulators
another UHF connector
Likely places to get the linear amplifier, connectors and cables is a Ham Radio swapmeet, a Ham b newsletter's classified ads, a Buy-Sell-Trade paper like The Recycler, or at a store specializn n Ham gear.
RF modulators are available at specialty video stores, or major VCR dealers.
Setting Up the Transmitter:
Using a VCR with RF out:
[VCR/RF]F--------------U[Linear Amp]U------------U[Antenna]
weak RF Power RF
Using an External RF Modulator:
[VCR]R----R[RF Modulator]----U[Linear Amp]U--------U[Antenna]
video weak RF Power RF
Diagram Symbols:
U UHF-connectors (Ham radio)
F F-connectors (cable TV)
R RCA connectors (stereos)
--- coax, cables, wires
[] devices (name of device in brackets)
<I> ceramic insulator (the kind with a hole at each end)
Building The Dipole Antenna:
wire wire
<I>---------------------+<I>+----------------------<I>
| |
Short coax | |
[U] UHF connector
The antenna is set up much like a clothesline with the wires tethered straight out horizontally.e outer insulators are used to isolate the antenna from the tether lines, which should be rope o yon cords for good results. The inner insulator i
solates a gap between the two long wires of the antenna.
The length of the wires used for the antenna is critical. Look up the length in feet for the chal you want to use in the table below & make each of the two long wires that length.
As a rule of thumb, a wire half-wave antenna's length in feet is equal to 468 divided by the frency in MHz.
****************************************
VHF Television Channel Data
----------------------------------------
TV MHz ---carrier--- antenna
channel range video sound lengths
------- ----- ----- ----- -------
2 54-60 55.25 59.75 8.47ft
3 60-66 61.25 65.75 7.64ft
4 66-72 67.25 71.75 6.95ft
5 76-82 77.25 81.75 6.05ft
6 82-88 83.25 87.75 5.62ft
7 174-180 175.25 179.75 2.67ft
8 180-186 181.25 185.75 2.58ft
9 186-192 187.25 191.75 2.49ft
10 192-198 193.25 197.75 2.42ft
11 198-204 199.25 193.75 2.34ft
12 204-210 205.25 209.75 2.28ft
13 210-216 211.25 215.75 2.21ft
(All frequencies in MHz)
(Lengths are for half-wave antennas)
****************************************
For Further information: Look in the ARRL Handbook published by the American Radio Relay League detailed plans & theory for antennas, transmitters & linear amplifiers. The info in that book cnb used for setting up an underground AM or FM radi
o station.
Uses for a TV Clandestine Station:
Public Education: Make a videotape of each step in the process of constructing your transmitter.ow this tape in your broadcasts, "For informational purposes only", of course.
Short-burst zipping: From a fixed or mobile base of operation show short snippets of graffiti-licomputer graphics, quick subliminal messages, images & suggestions, or brief phreaker manifestos omercials are an opportune time to break into TV
broadcasts.
Live call-in shows: Using a Cheese Box, or other device for receiving untraceable phone calls an video camera do a live call-in show. Encourage people to call in using Red, Blue, and other phraig boxes.
Cable TV Piracy: With modifications it may be possible to feed the power RF signal directly intocable TV system, overriding cablecasts or commandeering unused channels.
Mobile Operation: Using storage batteries and a 110-volt inverter the transmitter may be modifieor mobile use to avoid detection by the FCC during long broadcasts. Battery operated mobile lineraps and portable camcorders are also available.
Build this 5 to 45 watt FM amplifier.
25-200MHz / 8-45W AMP
--------------------O input
| D1 |
*-------|>|---- --)|--
| R2 -- | C1 | R1
*---/\/\/-----*----------|-/\/\/---
| ^ | |
| C2 | R3 | |
*--)|-*----/\/\/----*----- |
| | |
| / |
| \ |
| / R4 |
| \ |
| | g |
| Q1 ----- |
| ----- |
| s| ^ |d L1 |
*-------------------|_| |-*-(()((-*
| < C3 L2 | |
*-----)|---*-------(()((--| C5 |
| | --)|--*
| | > output | C6 |
| --|(----O -----)|--*
| C4 |-----| |
-------------------- --- |
- +12-24V
Symbols Key
=============
> g
-|(- = trimmer capacitor -----
----- = RF pwr trans.
-|(- = capacitor | ^ | g)ate s)rce d)rain
s|_| |d
-/\/\/- = resistor
* = connection point
-(()((- = coil
__ --|-- = jump (not connected)
-|>|--- = Zener diode ___
-- _ = ground
Component Listing
=================
R1 - 2.5K ohm L1 - 5 turns, #18 varnished,
R2 - 20K ohm trimmer potentiometer 5/16" inside diameter
R3 - 68 ohm
R4 - 10 ohm L2 - 3 turns, #18 varnished,
C1 - 220pF Tantalum, 35 volt 5/16" inside diameter
C4 - 16-100pF trimmer capacitor
C2,C6 - 4.7uF Tantalum, 35 volt D1 - 1N5230 (4.7V Zener diode)
C3 - 8-50pF trimmer capacitor
C5 - .1uF ceramic disc capacitor, 50 volt Q1 - (see chart)
Transistor Data (input --> output at 100MHz, 24 and 12 volts)
===============
PART # IN OUT IN OUT
------ ---- --- ---- ----
MRF134 - 0.4W --> 8W || 0.6W --> 3.5W
MRF136 - 0.4W --> 19W || 0.6W --> 8.5W
MRF137 - 1.0W --> 45W || 1.0W --> 17W
MRF138 - 1.5W --> 45W || 1.5W --> 15W
[24V] [12V]
* ASSEMBLY: Watch it with static around the TMOS transistor. It is VERY sensitive. If there's anyatic voltage difference between the drain or gate and the source, you can toast it! Keep it in h tatic-proof bag in which it was shipped until you
're ready to install it as the LAST component. Then solder the source tabs first, then the gate (osite diagonal tab) and
drain (diagonal) tabs. (See diagram:)
S /\ __ D
\ \___/ /
/====\/MRF\/====\
| O | 137 | O | <--- mtng flange
\====/\___/\====/
/ / \ \
G \/ \/ S
Mount the TMOS flange to a metal box with some heatsink compound. Ground your PCB to the same cabi.
* TESTING: Connect the output to a dummy load which can handle the power level you'll be generatingSet the trimpot at mid-range and apply your 12 or 24V. At this point, the power transistor shoulntget warm until you turn the pot up more. If it
does start to warm up, turn the pot down a bit until the temperature remains the same or lowers. DOT adjust past this point. Now feed your RF signal to the amp's input. Use C3 (tuning) and C4 la) to adjust for maximum output. You may also ha
ve to readjust R2 for the best reading. Keep an eye on the meter for sudden jumps in output - thisouldn't happen.
* TROUBLESHOOTING: If tuning is erratic, the amp is probably going into self-oscillation which can caused by insufficient grounding, bypassing of the power supply leads, too long of input or outptwres, or too high a bias.
* PARTS: Contact "RF Parts" at 619-744-0728 for the transistor you choose. Ask them for their lateflyer, too. It's free. Your local electronics supplier other than Radio Shack ought to have evrting else you'll need (at least mine does!). If n
ot, try "Mouser Electronics" at 800-346-6873 and get their free
catalog, too.
Build this high performance J-Pole antenna.
3 Meter Slim-Jim Antenna (JIM = J Integrated Match)
| | <-- spacing: 3" at 72MHz
_________ ____ _________
^ 90 degree --> / \ ^
| copper elbows | | |
| | | <-- 1/2" pipe elements |
| | | |
| | | |
| ^ | | ^ |
| | | | | arrows indicate | 1/2
| | | | | current direction | wave
| | | | | |
| | | |
| | | |
| 7.8' (89.5MHz) | | |
| | v --> sleeve for tuning |
| | ---> 3" air gap _______V
| | | ^
| | | |
| | | | ^ |
| | | | | |
| | | | | | 1/4
| v | | | | wave
| | | |
| * X <- tap *=ctr conductor |
| | | X = shielding|
v_________ \____/ _______v
NOTE: Adjust 1/4 wave and 1/2 wave section lengths as follows:
1/2 wave section=5610/MHz Example: 89.5MHz = 5610/89.5 = 62.68"
1/4 wave section=2805/MHz 89.5MHz = 2805/89.5 = 31.34"
* 1/4 wave freespace=2953/MHz 89.5MHz = 2953/89.5 = 32.99"
* distance that antenna should be from mounting boom, mast, or tower.
DESCRIPTION:
============
This is a vertically polarized omnidirectional free space antenna which offers approximately 1.8of gain. It has a radiation efficiency 50% better than a ground-plane antenna due to its low raiton angle, it is unobtrusive, and has no ground-p
lane radials - therefore low wind resistance.
Why Slim Jim? Well this stems from its slender construction and the use of a 'J' type matching b (J integrated matching = JIM) that facilitates feeding the antenna at the base thus overcomingadproblems of interaction between feeder and anten
na. The feed impedance is 50 ohms.
Why is the Slim Jim so much more efficient than the popular 5/8 wave or other ground plane anten, despite the latter's claimed 3dB over a dipole? The Slim Jim vertical angle of radiation is ams parallel to ground so maximum radiation is wher
e it is needed: straight out and all round. (The included diagram illustrates that the vertical angfrom the SJ is 8 degrees, while the common 5/8th wave ground plane antenna is about 32 degrees.) ih all ground planes, including those with radial
s an entire wavelength long, the vertical angle radiation is tilted upwards at an angle of 30 degreor more.
This gives the Slim Jim a gain over a 5/8th wave of 6dB when measured parallel to the ground!
OPERATION:
==========
Basically it is an end-fed folded dipole operated vertically. The matching stub provides a low edance feed point (50 ohms) at the base and couples to the antenna section at high impedance at n nd. As with all folded dipoles, the currents in
each leg are in phase, whereas in the matching stub they in phase opposition, so little or no radion occurs from this. (See diagram for current direction arrows.) Correctly matched, the VSWR (otge Standing Wave Ratio) will be much less than 1.
5:1, and remains so across the band.
CONSTRUCTION:
=============
The Slim Jim should be constructed from 1/2" copper pipe. The bends are made with soldered 90 dee copper elbows. A slip sleeve made from copper can be added to the element above the gap for uig purposes, although the average length of the ga
p and spacing between the elements is 3" at 72MHz and 1" at 220MHz. No part of the antenna should grounded to the tower or mast. The recommended mount is the use of PVC pipe and PVC pipe "T's." Make sure the space between the tower or mast and the antenna is one "freespace" 1/4 wavelength.ESTING:
========
Stand upright (on a railing or something, but clear of metal water tanks, drainpipes, etc.) andt the coaxial cable to the antenna with some crocodile clips. Attach about 2 inches up from thebtom and check the VSWR. Adjust the clips up or do
wn to get the best match (mine managed 1.2:1), mark where they are to go, remove the clips, and sor the coax directly. Use the copper sleeve, if added, for any necessary tuning.
A 15 Watt Phase Locked FM Transmitter
This simple little phase-locked transmitter is both easy to build, and extremely stable. It willt frequency drift, like the other transmitters presented in this book.
The frequency is set by first adjusting the variable inductor in the oscillator circuit to near desired frequency. After the oscillator is close, program the dip switches with the desired freuny.
The dip switches are programmed with a binary representation of the operating frequency. For exae, if the frequency is 88.1 Mhz, you would take the binary of 881, which is 000011101. A one meastat the switch is on the 'ON' position. Note that
the right most bit is 1024, and the left most is 1.
PLL Transmitter 1
PLL Transmitter 2
PLL Transmitter 3
PLL Transmitter 4
The BA1404 stereo transmitter IC
Around 1988, the Rohm company introduced a revolutionary IC. This IC has a complete stereo generr and transmitter on chip. This allows one to build extremely small and light-weight transmitter. The main drawback of the BA1404 is that it only has an output of 8 to 10 mW. This can be amplifi. ee the FM-10 section.
Following are complete specifications for the '1404, as well as a couple good schematics for conucting a transmitter that is similar to the Ramsey FM-10.
BA1404 Specs 1
BA1404 Specs 2
BA1404 Specs 3
BA1404 Specs 4
BA1404 Specs 5
BA1404 Specs 6
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