This Unit was originally manufactured back in the 80s, and sold exclusive to Law Enforcement. It has an RF output of around 3 milliwatts RMS. It was built using surface mount with back to back boards the size of a postage stamp combined with a 3V button cell battery. The unit was used with an RF Repeater concealed in the trunk of an automobile nearby. It has also been manufactured using 1/10th size TTH components, on a drilled board (Standing Up). I have used various standard audio (Q1 and Q2) and RF Transistors (Q3, Q4 and Q5) over the years of the PN plastic type that worked well when I built it - thru the hole - so if you go that route, rather than surface mount - just experiment with different transistors. Most all will work.

 

150xt Transmitter
© 2012 By John S. Wilson Jr.
john@bugplan.com

Transistors: Digi-Key Electronics

Q1 Q2 and Q3 - MMBTA20 - Digi-key Electronics

Q4 and Q5 - MBTH10L - Digi-key Electronics

V1 - MMBV2109 - Digi-key Electronics

XT - 15 or 16 Mhz Crystal. - 15 Circuit Operates @ 150 Mhz. 16 - 160 Mhz

Digi-key Electronics CA-301 Barrel Crystals Will Work ( They Are Cheap )

L1 - .15uH

L2 - .10uH

Battery: 3V Button Cell if Surface Mount - Or 2 AAA Batteries in series TTH

Antenna: 16" Small Stranded Wire

Watch The Video Below Of Pete Zenners Demo of this Circuit, and then click into the links - below that video to see his assembly

 

 
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Crystal Controlled FM Transmitter - 150xt

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