HIR Issue 1: How to build your own telephone bug
A Hacker's Information Report Article by Axon
Now, of course, this article is going to display the principle of radio transmission, as well as showing how to use an alternative power source; therefore this article is completely educational. You'll even get to practice soldering! Wheee! (By the way, listening to someone else's telephone conversation without their permission is against the law, and it's also mean. Never attempt to bug my telephone. I'll find it as soon as I pick up the phone. Don't point fingers at me if you get busted for doing something non-educational with this info...snicker)
The first thing I would recommend to all you crazy hacks is to scroll to the BOTTOM of this text, and ogle at my Ascii-Schem for how to make this awesome device. I may put a Gif version of the schematic up on the HIR Distro site later if i get a whole lot of complaints. Note the parts list under the scheme ... jot all those things down, and go to some place to get them. You may need to special order the transistors, but probably not. Radio shack might have them, or an equivalent. Just ask and they'll look through a huge old book to find equivalents.
Now that you have your parts, let's continue ... I expect most of you should be able to assemble it from the scheme. You will probably want to etch a small pc-board (I've fit this project on a board as small as a quarter), or something. This is REALLY simple.
To make the coil, take the 6 inches of enameled 28 gauge wire, and scrape the enamel off the ends (1/8 inch is good) and wrap the wire tightly around a pencil, and carefully remove it, taking care to keep its shape. If it gets deformed, you are screwed. Redo it.
Since this article is educational, I might as well teach you guys how all this crap works together to send a fone conversation over the radio waves. This device is a combination of a high frequency oscillator, and a voice amplifier. The voice amplifier takes the signal from the phone line, and uses it to modulate the oscillator, causing a nice clear FM signal. Let's take a look at what's happening inside out little circuit.
The parts of the bug that makes up the oscillator circuit are Q1, L1, C1, C2, C3, C4, R2, and R3, and a power supply, which happens to be the phone line (wow! No batteries or nothing?!) Q1 is Biased into conduction by R2. The collector of Q1 is attached to L1, and C2, 3, and 4. This array of coil and capacitors happens to cause an oscillation ranging between 88MHz and 108 MHz, depending on how the trimmer capacitor is adjusted. This range of frequencies is typically known as the FM (frequency Modulation) Band. That's right, the stuff your FM radio can "hear".
Q2 and R1 make up the Voice amplifier, which is used to amplify the audio signal, and is then used to modulate the signal that the oscillator is generating.
Okay, so how do we hook this up, find what frequency it's on, use it, etc?
Well, ya gotta hook it up first. Testing this device requires a phone line, a phone, and an FM radio that you can have close to the phone. To hook it up, you have to put it between the phone. This will be hooked up sort of in series with the phone, and kinda parallel, too.
Green wire: Hook this up to the green line wire on the FAR side of the fone.
Gray wire: Hook this up to the green line wire on the NEAR side of the fone.
Red wire: Attach it to the red wire. IT just needs to make contact. Don't Cut the red wire, and if you do, twist all three red wires back together.
green line wire/green bug wire Gray Bug wire Green fone wire|""""""|
---------------*--------|"""""|---------------------*---------------| |
| BUG | | FoNE |
|_____|--| <---RED Bug wire | |
---------------------------------*----------------------------------|______| To test it, tune to an empty station on your FM radio, one with only static. pick up the fone your bug is attached to, and then adjust the Trimmer slowly (preferably with something insulated or plastic) until you hear the dial tone (or if you wait too long, the "We're Sorry..." message) on the radio. make sure you aren't touching any of the wires (especially the coil) as this will slightly change the frequency when you release it. You now have a working bug. IF you just can't seem to tune it in, check to make sure you don't have any loose connections or solder bridges. IF that doesn't work, try using a different empty radio channel.
For permanent installation, you may want to mount it inside a project box, with one male, and one female RJ-11 jack sticking out so you can just plug it straight into any normal fone line, or you may consider mounting it INSIDE a telephone. This device is small enough. As far as the Antenna, I've tried various things. you may want to make a long wire, or just hook the antenna wire up to the yellow modular wire (which is used for a second line. This will not, however, mess up their second line if they have one, just make it a huge antenna. You may be able to pick up the conversations from as far away as a quarter mile. Good luck!
Ascii-schem for telephone bug …ÕÕÕÕÕÕÕÕÕÕÕÕÕÕÕÕÕÕÕ
by Axon ∫ Legend
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gray wire ƒƒƒƒƒƒ¬ƒƒƒƒƒƒƒƒƒÕπ ≥ ≥ ∫ ÈÈÈÈÈ = coil
≥ R1 ê ≥ ≥ ∫ ÃÕÕ
¿ƒ\/\/\/ƒƒƒ¥ ≥ ⁄ÈÈÈÈÈŸ ≥ ∫ Õπ = transistor
47Í ≥ ≥ ≥ L1 .___. ≥ ∫ ÃÕ
green wireƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒŸ ≥ ≥ \ / ≥ ∫
R2 ≥ ≥ ≥ ≥ ∫ .___.
⁄\/\/\/Ÿ ≥ ≥ ≥ ∫ \ / = Antenna
≥270KÍ √ƒƒƒƒƒ¬ ≥ ≥ ∫ ≥
≥ Q1ÃÕƒŸ C2¡VARIABLE ≥ ≥ ∫
√ƒƒƒƒƒƒƒÕπ5pF-40pF¬ ≥ ≥ ∫ \/\/\/ = resistor
C1 ¡ ÃÕø⁄ƒƒƒƒ≈ƒƒƒƒƒƒƒƒƒŸ ≥ ∫
100pF¬ R3 √Ÿ C3¡ ≥ ∫ ¡
red wire ƒƒƒƒƒƒƒƒƒƒƒƒƒ¡ƒƒ\/\/\/ƒƒƒ¡ø47pF¬ ≥ ∫ ¬ =Capacitor
680Í ¿ƒƒƒƒ¡ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒŸ ∫
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Resistors Capacitors Transistors
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R1 = 47 Ohm ¨Watt 5% ≥≥C1 100pF Cer. ≥≥ Q1 2N3904 ≥
R2 = 270K Ohm ¨Watt 5%≥≥C2 Trimmer 5-40pF Variable≥≥ Q2 MPSA56 ≥
R3 = 680 Ohm ¨Watt 5% ≥≥C3 47 pF Cer. ≥¿ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒŸ
≥≥C4 470 pF Cer. ≥ Coil = 6 inches of 28ga
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Green, red, gray wires are 22ga solid preferably Previous part of
text for how to make it 
