VHF FM Transmitter Circuit Built By Pete Zenner

VHF Transmitter Circuit BBG Built By Pete Zenner

VHF FM Transmitter Circuit, XTAL Locked  - BBG  1/2 Watt Crystal Controlled
Built By Pete Zenner, Sioux Falls, SD.
I made a couple of additional changes on my PCB layouts of your BBG fm transmitter circuit, schematic. This was the smallest I could reasonably get the board size. As you can see, it now fits into a Sucrets box with a 9V battery. Now that it all works properly ( flipping the varactor diode the right way around helped ) and I have a PCB that fits the parts I have on hand, I can now move on and make - generate a bunch of boards at once.

Because most other professional transmitters (LEA, DTC, SpectraTek, etc.) use an antenna connector, I opted to buy a bunch of SMA connectors and make a tuned antenna. I also added a microphone jack that you can swap different mics in case one breaks, etc.

I appreciate all the advice and encourage you gave me. This has been a fun project.
xtal locked, crystal controlled fm transmitter circuit
fm transmitter circuit in enclosure
Update -    Pete Jenner Has Built  another  BBG, this time in an "ALTOIDS" Tin Box.
Below are the photos he emailed me and - also some Tips for building the BBG in this type of Enclosure.
Some tips for your builders. Working with Altoids tins as an enclosure is a great field-expedient. They are readily available, easy to work with, and the same size as expensivetransmitters. However, measure the center of the holes carefully. The holes should be equally spaced from the bottom of the lid to the bottom of the tin.  Drill the holes undersize. The tin tears easily, even with the sharpest drill bits. Use a hand-reamer to get the proper fit and keep the holes round.

Cutting a square hole for the SPST switch is a little more difficult - but again, mark and measure, then drill some undersize holes side-by-side. Use a small file to shape the opening to the right size,and test fit your switch often. Again, make sure the hole/opening are underneath the lid but don't interfere with the PCB board. Trial fit allcomponents.

Use the smallest jacks  and connectors possible.  The mic jack is  a Switchcraft TR2. Insulate the bottom of the tin. I use overlapping strips of electrical tape. A very thin piece of plastic could also be glued down. Then I hot glue the board to the bottom of the tin--onto the tape. A builder could use plastic stand-offs or washers, but they're not necessary.There is not a lot of  extra room in these tins. Everything will be snug, but they will fit.

Pete, Sioux Falls, SD
law Enforcement VHF Transmitter Circuit
fm transmitter - Law Enforcement Grade in Enclosure
End View Of FM transmitter Circuit
Enlarged View Of FM Transmitter Circuit
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