I have a stromberg-Carlson radio receiver(No.400 H) that I would like to repair. I think all the tubes lights up but I not sure because two have black glass or are incased. Suggestion will be great appreciated.
How to test the tubes to see if heaters are OK. Power up the radio. Make sure that capacitors are not hot and fuse does not blow (or you can disconnect B+ at all). Eait about 10min and touch the tube. If heater is OK then the tube will be warm.
Those metal tubes can get pretty hot - shouldn't be any doubt once it's been on a few minutes...
ect. Some hum is a good sign.
If there's no sound at all from the speaker, the speaker field coil or output transformer is susp
Schematic is here: http://www.nostalgiaair.org/PagesByModel/498/M0021498.pdf
No voltages listed - but if you can measure the voltages at each tube socket pin, it shouldn't be hard to diaqgnose. BUT... if you haven't worked with high voltage before, you should find an experienced person to help and point out the hazards. This set has a power transformer, so shock hazards are less likely but MORE DEADLY.
ect. Some hum is a good sign.
If there's no sound at all from the speaker, the speaker field coil or output transformer is susp
Schematic is here: http://www.nostalgiaair.org/PagesByModel/498/M0021498.pdf
No voltages listed - but if you can measure the voltages at each tube socket pin, it shouldn't be hard to diaqgnose. BUT... if you haven't worked with high voltage before, you should find an experienced person to help and point out the hazards. This set has a power transformer, so shock hazards are less likely but MORE DEADLY.
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