Pete Zenners 150xt FM Transmitter Circuit Photos

Pete Zenners Assembled 150xt Transmitter Circuit

I finished the 150xt yesterday.

The enclosure is the nice part--it's just a plastic cassette case which I spray painted black. It's very easy to modify, drill and cut. I used hot glue to keep a thin piece of rubber under the circuit board, then hot glued the circuit board onto the rubber. The two coils are 5mm "Unicoils" from Coilcraft. The violet is 7 turns and is 156nH with the core removed. The green is 5 turns and is 99nH with the core removed. The crystal is a common 16MHz with a 20pF load capacitance. It was ordered from overseas at a great discount on eBay. The final frequency tunes at 160.050MHz.

A small hole was punched for the antenna wire. A power switch was added and its hole carefully cut with an Exacto knife. 4x AAA rechargeable NiMH provide 4.8 volts. The battery holder still fits inside the slim cassette box.
The design may be simple, but the results are sturdy and professional. Clear audio. A good range. And inexpensive and easy to build. The design is flexible and allows using substitute and junk-box parts. Some of small capacitors values were changed to my nearest available value... i.e. 22pF to 27pF, etc. I'm making a few more of these. Pete

Assembled 150xt Transmitter - By Pete Zenner

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Circuit Board Board View - 150xt FM Transmitter Circuit
Inside View, Assembled 150xt Transmitter Circuit
Return to the 150xt FM Transmitter Circuit
Down View, Assembled 150xt Transmitter Circuit