CoRadio Help

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CoRadio Help

RodB
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Posts: 1,192
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Joined: Feb 2015
City: Roseville, MN

01-13-2023, 10:48 AM

Try checking voltage at pin 5 of the 12SA7 with a DMM. You should measure -2 to -4 volts if the oscillator is running. If it's zero there's the problem. Start by re-checking the oscillator solder connections, coil continuity, clean tube socket pins, pin 4 should measure B+. The capacitor connected to pin 5 is usually a mica and sometimes it can fail. There's usually a 22K resistor connected to pin 5. If it's more than 24K, replace it.

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CoRadio Help - by mister_big77 - 01-12-2023, 10:26 PM

RE: CoRadio Help - by Radioroslyn - 01-12-2023, 10:52 PM

RE: CoRadio Help - by Radioroslyn - 01-13-2023, 10:00 AM

RE: CoRadio Help - by mister_big77 - 01-13-2023, 10:18 AM

RE: CoRadio Help - by RodB - 01-13-2023, 10:48 AM

RE: CoRadio Help - by mister_big77 - 01-13-2023, 10:49 PM

RE: CoRadio Help - by RodB - 01-14-2023, 11:06 AM

RE: CoRadio Help - by mister_big77 - 01-16-2023, 01:11 AM

RE: CoRadio Help - by MrFixr55 - 01-17-2023, 05:37 AM

RE: CoRadio Help - by mister_big77 - 01-17-2023, 10:10 AM

RE: CoRadio Help - by MrFixr55 - 01-17-2023, 05:33 PM

RE: CoRadio Help - by mister_big77 - 01-18-2023, 02:29 PM

RE: CoRadio Help - by MrFixr55 - 01-18-2023, 04:12 PM

RE: CoRadio Help - by mister_big77 - 01-19-2023, 11:14 PM

RE: CoRadio Help - by MrFixr55 - 01-20-2023, 06:55 AM

RE: CoRadio Help - by mister_big77 - 01-21-2023, 08:45 PM

RE: CoRadio Help - by MrFixr55 - 01-22-2023, 01:01 AM

RE: CoRadio Help - by mister_big77 - 01-22-2023, 02:31 AM

RE: CoRadio Help - by Arran - 01-23-2023, 06:23 AM

RE: CoRadio Help - by MrFixr55 - 01-23-2023, 07:07 AM

RE: CoRadio Help - by Arran - 01-23-2023, 08:59 PM

RE: CoRadio Help - by mister_big77 - 01-23-2023, 09:47 PM

RE: CoRadio Help - by MrFixr55 - 01-24-2023, 06:31 PM

RE: CoRadio Help - by mister_big77 - 01-24-2023, 08:30 PM

RE: CoRadio Help - by mister_big77 - 01-24-2023, 10:01 PM

RE: CoRadio Help - by MrFixr55 - 01-25-2023, 02:11 AM

RE: CoRadio Help - by mister_big77 - 01-25-2023, 11:04 AM

RE: CoRadio Help - by mister_big77 - 01-25-2023, 11:38 AM

RE: CoRadio Help - by MrFixr55 - 01-29-2023, 09:46 PM

RE: CoRadio Help - by mister_big77 - 01-29-2023, 10:56 PM

RE: CoRadio Help - by MrFixr55 - 01-30-2023, 07:06 PM

RE: CoRadio Help - by mister_big77 - 01-30-2023, 11:23 PM

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