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QRP 20 transmitter mods

by robotnut
Tags: mods, transmitter
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Jan8-10, 07:11 AM
P: 5
Hello all;

Wifey got me a 20M QRP radio transmitter (1watt) for X-mas, knowing I love playing with this stuff

I have never heard of QRP before and was very surprised to find that there is no audio input on it

So I stuck the kit together in about 2 hours and my spectrum analyzer has me convinced it is working on the assigned freq. It is a Ramsey electronics kit.
This kit comes with 2 crystal sockets and a crystal on the 14mhz band and a crystal selector switch.
The question:

What would it take to convert or mod this for audio transmission? My 2nd crystal is on the 27MHZ band for CB. I wanna so it because it would a fun learning experience and I already have a 27mhz receiver.
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Jan8-10, 08:56 AM
Sci Advisor
P: 4,032
That was a sweet present, but you must not attach an antenna to it and transmit if you don't have a Ham licence.

Your 27 MHz crystal is probably really a 9 MHz 3rd overtone crystal, so it is unlikely to work on 27 MHz in this circuit although you may hear a 3rd harmonic. Any radiated power would be mostly at 9 MHz.

If you have such an interest, why not visit a local radio club and meet some Hams? Maybe there is a course you could join to learn more about Radio and Electronics?

It is probably not realistic to convert this transmitter to AM as AM is not really used any more and it would also be quite a serious modification.
Some FM might be possible if you put audio on the R1 control instead of the 12 volts, but it would probably be pretty rough.

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