How to build a tiny FM Spy Bug

Learn how to build a ladybug sized FM spy bug. This one here measures only 0.05 sq inch and has a range of up to 150ft.

You won't probably be able to make it much smaller than the one described here. It uses a MEMS microphone (even though this is not the smallest yet) and a simple transistor oscillator circuit. The whole circuit is powered by a single 4.8mm diameter 1.55V silver oxide button cell.

The complete instructions and Gerber files (for PCB manufacturing) for this FM spy bug are available for free here:

and here:

This Covert listening device is probably the smallest anybody will be able to build at home. Its dimensions are only 4.75 x 6.8mm.

The transmitter circuit works down to a supply voltage of about 1.05V while maintaining exceptional audio quality.

In this video I show you how to assemble it.

[xiangyu]

Can i pay you to send me one of these?
cheaper than getting a hot plate and microscope etc
(UK)

[footinheavensdoor]

You can wet-sand the board to avoid breathing the fiberglass dust.

[rezanouri]

God bless German and German people, well done Tom

[matthewhopkins]

Indian guy. German news broadcast. Of course.

[krisztianmajor]

Can you paste to the description the full cart link for digikey with the parts?

[FantaBH]

Nice really nice work, but how you protect yourself from soldering paste when it start to release poisoned gas which present heavy danger for health. Every low temp soldering paste contain such chemical in it. You should note that in your video for all who do not know such thing and get amassed how you doing it so want to do same without knowing for danger. Anyway as you did great job I left great big like .

[tomweickmann]

Bought a kit like this. SMT parts.
I ruined it.

[Tech-shop]

please can you tell us how you build the board

[Aussenwerbung]

Bist du noch aktiv? Ich muss dich erreichen.

[nor]

Is there any money in it, if you sell this as a kit

[hunter]

Well done but unstable design due to lack of xtal.

P's As a kid I found my AM crystal set would transmit on long wave by speaking into my 4k ohm earphones no batteries required.

[compufreek]

Great instructable, how long does it operate ?

[BarefootBeekeeper]

I need a version of this with an oscillator built in for use as a tracker for large insects.

[the_eminent_Joshua_E_Hrouda]

Where can I buy a smaller microphone ? I don't mind if I pay $10 for it!!

[thevacuumtubejunky]

Where can this kit be purchased from???

[Tech-shop]

I mean how making the board this small size