[R-390] Product detector
Jacques Fortin
jacques.f at videotron.ca
Thu Sep 28 21:11:24 EDT 2017
Larry,
What if we let the AM detector output connected to the limiter control (R120, term 3) at all times, but we feed the output of the SSB demodulator to R527 ?
In my implementation of the Cap't Lee modification, I have put the relay changeover contact directly to R527.
In AM, R527 is then connected to J512-3 (like in a non-modified IF deck) and in SSB (BFO powered) R527 is connected to the 200pF 2nd filter cap that was going originally to the BFO "double" sw by using J512-1 in Cap't Lee article.
I do not use a supplementary negative voltage generator (the 1000µF and diode connected to the 25.2V and etc.)
In your opinion, does the negative voltage produced by the AM demodulator alone can be sufficient for the limiter when SSB signals will be received ?
What about also changing the R527 value to 62k ?
I remember having read something about to reduce the limiter stage distortion.
Let me know.
73, Jacques, VE2JFE
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