"Cecil Moore" wrote ...
Richard Crowley wrote:
So is there anything at 9 KHz that could be an intermittent
source of CW?

9 KHz is in the audio spectrum so it is probably
the product of mixing. What frequency is the
receiver tuned to? What are the IF frequencies?
What are the intermod possibilities?

It is being picked up directly by two Royer ribbon
microphones which contain an active impedance-
matching circuit implemented with a tube ("valve").
No IF involved there.

On his AM BCB receiver, he was complaining about
790KHz. We likely have no way of discovering his IF
frequency.