Philippe,
1. Use a sine wave quench (this will give best selectivity), with a separate quench oscillator
2. Quench frequency should be related to highest modulating frequency of the received signal, so about 10 to 15kHz should be about optimum - the lower the QF, the better the sensitivity.
3. Make the feedback for detector such as to have it oscillate strongly.
4. Make the quench level variable, and use the minimum quench level that allows the circuit to work adequately.
5. Especially if using the rx near an airfield, use a cascode RF amplifier (for reverse isolation) and a lot of screening to avoid causing interference
Hello Peter !
Thank you so much it is the first time I have a clear and concise answer.
Here are my remarks :
1 - A sine wave : why is it better ? On other forums, I have seen that no matter the waveform of the quench, but it is difficult to believe ... OK for a separate quench oscillator I have already started to test a sawtooth one
2-
Quench frequency :
the lower the QF, the better the sensitivity : Why ? Do you mean that the transistor (2N 2369 A) has a lower "workload" ? :-)
3- OK !
4- Quench level : OK I agree
5- OK but does it decrease the sensitivity or not ?
I would like to show you the schematic but I have asked the webmaster, alas no way to embed an image in the message !
Again thank you for your help
Best regards
Philippe
F1 CUJ