Dynaco FM3 hum

Radio Road

Which tuner to get and getting the most from it. Thank God, for the radio!

So it turns out after about 15-20 minutes a minor hum develops in my FM3. The big 40/40/20/20 can does get pretty warm, almost hot. I am thinking this is likely a contributor if not 100% cause of the hum.

Prior to the 15/20 minutes use, the FM3 is dead quiet, no hum or hiss.

I have a replacement on the way from Antique Audio. Due to aging and heat exposure I presume all the boards, traces, and solder joints are very fragile.

Two questions:

1: Any tricks to minimize causing new problems in the boards while R&Ring components?

2: Since I had the tuner powered up for a couple hours recently, I need to be concerned about the caps holding a charge after power was disconnected. Could I be sure they are discharged by switching the unit on with a load without being powered up? I do have a "snuffer stick" but I worry I could miss a cap and I am not very experienced reading schematics...

Any other tips to R&Ring components for this unit?

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Kimber Kable

Topic - Dynaco FM3 hum - ltman 12:23:19 11/26/23 (12)

Oh, sorry. You said Dyna-co - M3 lover 09:49:04 12/13/23 (0)

ESL has a power supply PCB - Cougar 19:00:23 11/28/23 (1)

RE: ESL has a power supply PCB - ltman 06:59:46 11/29/23 (0)

: Dynaco FM3 hum - much reduced! - ltman 17:22:46 11/28/23 (3)

Yes, the 6V4/EZ80 is the rectifier tube - 1973shovel 12:47:49 11/30/23 (2)

RE: Yes, the 6V4/EZ80 is the rectifier tube - ltman 20:28:36 12/29/23 (0)

RE: Yes, the 6V4/EZ80 is the rectifier tube - ltman 12:07:51 12/02/23 (0)

RE: Dynaco FM3 hum - fredtr 12:37:59 11/26/23 (4)

RE: Dynaco FM3 hum - ltman 15:05:02 11/26/23 (3)

RE: Dynaco FM3 hum - 6bq5 10:48:21 11/27/23 (0)

RE: Dynaco FM3 hum - fredtr 15:29:54 11/26/23 (1)

RE: Dynaco FM3 hum - ltman 22:53:22 11/27/23 (0)

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