I am going to show you a step-by-step process to building a spybug from common electrical componenets.

Step 1: Components

Components list

Part

C1 1n disk capacitor (102) 1 pc.
C2 5.6pF disk capacitor(562) 1 pc.
C3, C4 10 uF Elec. Capacitor(25-50v) 2 pcs.
C5 3-18 Trimmer Capacitor 1 pc.
R1 330 ohm 1/8 w Resistor 1 pc.
R2, R5, R6 4.7k 1/8 w Resistor 3 pc.
R3 10k 1/8 w Resistor 1 pc.
R4 100k 1/8w Resistor 1 pc.
Q1, Q2 2N2222 NPN Transistor 2 pcs.
L1, L2 5-6 turns copper coil 2 pcs.
10mm Electret microphone 1 pc.
9v battery and clip

All Resistors can be substituted with 1/4 watt. The transistor can be substituted with a 2n3904-06 transistor.

Step 2: Schematic

Here's the schematic, any questions leave them I will answer quickly as possible.

Step 3: PCBV Layout

Here is a picture of the PCB that I made for this spybug, or you could just make it on perfboard if you want.

Step 4: Resistors

First I soldered the resistors on just below where the mic will go. These are R5 & R6.

Step 5: Adding Components

Next I add C4 (10 uF cap), Q1,Q2 (2n3904 transistor) & R4 (100k)

Step 6: Adding Components

Next step I add the electret microphone, and the two coils. The coils should be wrapped around a 1/4 inch drill bit 6 times to get the coil needed for this project.

Step 7: Adding Components

Now I add C1 (102) capacitor, R1 (330 ohm res.), R3 (10k res.) and C4 ( the other 10uF capacitor)

Step 8: Adding Componenets

In this step I add the last resistor (R2), then I checked to se if every coponent is where it should be just to be sure.

Step 9: Adding the Trimmer, Etc.

Finally comes the trimmer cap, the battery connector and the antenna wire. I chose to use a braided copper wire for this antenna just to try it but you can use whatever you like.