Re: AR88 Low HT
Success! After tracing things out it became apparent R43 was in fact missing completely. I later found it under the table I'm keeping the set on, it must have been loose in the case when I got it and didn't realise when it fell out.
I replaced this with a new 5w resistor as I had done with R44. I also identified the other resistors nearby and replaced R53, R36, R37 and R45. They were either visibly heat damaged, or were out of spec. When R44 had burned it made a hole in the paxolin(?) board underneath, so you can imagine parts near it were not in the best shape.
The receiver now powers up, I'm seeing 156v on the stabilised rail, and 304vdc wrt chassis at the anode of the output valve. All bands work to some extent and I can pull in at least something on all with just a 4 metre ength of wire in the back in a concrete building. The receivers ground tag is shorted to chassis and the set is mains earthed. Bands 5 and 6 seem weaker than others, the wave change switch could use a clean, along with the pots. No apparent faults, but this is my first proper comms receiver so I can't say for sure. It does wipe the floor with any portable shortwave device I've used!! I managed to catch a bit of CW so the BFO is at least doing something.
I think at this point I'll continue with the usual tasks of neons on the output TX, bathtub rebuilds and go from there
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