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HH Scott 340 power supply voltages?

Posted by halftime2020 (A) on October 3, 2014 at 17:33:23

New to this forum...

I am restoring a HH Scott 340B. It is in excellent shape. I have replaced the P.S. caps, signal couple caps, Selenium Rectifier, added a series resistor, etc.

There is still area few issues to solve:
1. A minor hum in the audio. Traced to poor ground, but there still is a small amount in the audio signal. Otherwise, audio is exceptional.

2. No FM section. Tubes appear to be good, but there is no signal even with a good antenna. The HH Scott schematic lists voltage in the FM section and while they appear to be correct, there are a few that I am questioning and might be the culprit to the FM section not operating in my unit. Thus, I have reverted back to the power supply to determine voltages are correct.

Has anyone measured the voltages coming from the power supply? Specifically, R307 and R308. The HH Scott schematic lists R307 as 1K, 1W. The original resistor in the system is 200 ohms, not 1K. I think that is incorrect. R308 is 750 ohms, 4 watts. That resistor was a little too hot, so I replaced it with a 10 watt.

Thanks in advance!

Rick

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