Jim,
Thanks for the pointer regarding that electrolytic capacitor on the power supply board. No, I did not change it when I had the board out. I will make a note for the future, but will not disturb the board again until I have the transmitter-side working. The Heathkit Shop used to make a nice-looking, replacement power supply board for the TR-7, but not sure whether they still do. I recall mailing the owner a few years ago and he was not willing to ship to the UK because of all the trading complications resulting from the UK leaving the EU. I see there's a potential alternative here: but not sure whether these are in production and for sale yet.
"The band switch detent is pretty light on these. Is is the ball and leaf spring at the rear. The stiff wire attached to the the bulkhead between sections is a ground point for the shaft." Mine does not have any ball and leaf spring. Probably fell on the floor of a previous OM's shack, along with some of the screws:-( If you or anyone has a picture and/or any dimensions of how things should be, I would be grateful. Otherwise, I will figure it out.
I do have another TR-7 - a very nice, late model, made just prior to when Drake started producing the TR-7A. Plus / minus some minor connector oxidation issues, that one has always worked well. Problem is, when stuff just works, there's little incentive to learn much about what goes on inside. Fixing up this 'basket case' TR-7 has forced me to understand the design, which will be good for maintaining the 'fleet' in future. Having needed to get to the LPF and HPF areas of the radio, I now understand why Drake decided to split the rear panel in the later models!
Regards,
Mark, G4FPH.
