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Hi All,

Here is another note on the above transceivers (applies to both models).

I noticed that the received signal seem "gravelly" or "raspy". This seemed to be worse on strong signals and initially I thought that it may be an overload issue. Upon further investigation, I noted that the BFO frequency was being pulled by the product detector. The plate of the BFO tube is connected to the cathode of the product detector through a 120pf capacitor. As the signal at the product detector varied, the impedance of the cathode circuit varied and changed the loading on the plate of the BFO. This was very noticeable when monitoring the plate circuit of the BFO oscillator.

I added a 100pf cap in series with the existing 120pf cap that is between the BFO plate and product detector cathode to reduce the interaction. This appeared to clear up the problem with the BFO frequency changing as a result of the received signal. I did not yet try a different BFO oscillator tube to see if it might be a tube issue.

I know these are not common rigs, but I wanted to document my experiences with others. I will post some additional notes as time permits...

Bob,? K7DYB