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radio transmitter
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radio transmitter

by wing23 on Wed Feb 09, 2011 1:02 pm

Hey all!

I stumbled over this place while looking for cell phone jammer circuits and then found the wave bubble.
Happily I found out, that there's a new project going on, but that's another thread.

Since here are people who seem to know a lot about transmitters and electronics (electronics is one of my hobbies, but I'm no engineer so I often don't know how to design special circuits from the scratch), I thought I could ask something related here:

For several years now I have a small project, a radio transmitter. But it doesn't really work like it should.
There are lotsa circuits on the internet, some years ago I found one using a Pic16f84,LCS and a TSA5511 as PLL. I build it along with a very small transmitter.
Though I can recieve the signal (over 200-300 meters, including RDS and stereo decoding) it doesn't work to my satisfaction.

Like I said, the internet is full of circuits, several sites list the same few circuits and projects, but none really works.
when building them, it's also needed to make coils yourself, using some turns of wire.
My circuit for example can't adjust the frequency. Changing it via the Pic controller does nothing. All I can do is to turn the adjustable caps on the transmitter board, but that's not how it should be done.

Would it be possible for you to design a circuit (maybe as a new project for adafruit) that works like the wave bubble, along with a good transmitter circuit, that won't jam frequencies that are not on the 3m band?
I looked everywhere, but there's nothing that uses a VCO (like wave bubble does), a mega8 and PLL. And all transmitters I found use the same transistors and I wonder why they work at all, looking at the design of the boards ... I don't know, but I guess 5 or 10 W would be sufficient.

Thanks for replies, help or anything else :)
Posts: 17
Joined: Tue Feb 08, 2011 11:32 am

Please be positive and constructive with your questions and comments.