Re: #qdx Passband AF filter #qdx

Alan G4ZFQ

On 28/06/2022 10:11, Jim G7FRI wrote:
Answering my own question… :)  It looks like it comes through via Q6…
Yes, Clock2, R19 and the selected LPF.


Your description of the audio trace does not seem right although the figures might indicate 20dB image rejection.
Normally in a radio like this there is either good rejection or none. A small variation in opamp gain might make 20dB difference. Look carefully make sure there is nothing making a short around the opamps. Check marked resistor values.

Do you use a dummy load?
What do the RF traces look like?

73 Alan G4ZFQ

Join { to automatically receive all group messages.