{Re: Beltron 8080: I just got lucky with this purchase. Saw it in the classified section of a ham website a few years ago. I had no clue whether it was good or bad.}
BLUNDER:
I checked the resistance data and it was all good, so I gradually turned up the power to 117 volts. All the tubes were glowing nicely, so I started to go through the voltage data table. It seemed that I wasn’t getting any B+ voltage, so I leaned over the set to look at the tubes again and I noticed an awful lot of heat coming off of R97, a 7.5 ohm 5W resistor/fuse.
Yes, I killed R97.
It didn’t take long to figure out that I had miswired electrolytic C1. Instead of connecting C1 negative to R97, I connected it to the common ground with the other electrolytics. I replaced R97 with a normal 7.5 ohm 5W power resistor and starting checking voltages again.
Now all of the filament voltages are good, but the B voltages are way low. When I last worked on the set five years ago, all the voltages were good. The red numbers on the diagram are my current readings. So, what did I break?
I’ve checked everything I know how to check. In all transformers my reading of DC resistance matches the specs (except I have no resistance data for T2, so I noted my readings on the diagram).
Link to full schematic:
https://picasaweb.google.com/lh/phot...eat=directlink
My knowledge only takes me as far as, “Maybe it’s T2?” Incidentally, the Stancor replacement, part P-6134, seems to be readily available.
What else should I be looking at?