[Collins] 51J4 audio improvements??

[Dr. Gerald N. Johnson, electrical engineer]

The crystal filter is not a benefit to AM reception. Its going to be
quite narrow, intended mostly for CW. The limitation to bandwidth
without a mechanical filter will be the last IF transformers. They may
need to be stagger tuned to achieve even 6 KHz bandwidth.

The audio stage coupling and bypass capacitors could be leaky modifying
the audio stage operating points. First step should be replacing any and
all black beauties with orange drops. Then you have a bunch less
troubleshooting to do.

Its almost sure that taking audio off the diode load to a good amplifier
will present better quality audio. Its not a HIFI receiver.

73, Jerry, K0CQ, Technical Advisor to the CRA
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Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.