SB-300/301 audio hum

[Dennis Norton]

Try scoping the B+ that feeds the audio stage. Look for ripple--if so,
suspect power supply filter caps are going bad...good luck.....Dennis Norton
W2DJN


----- Original Message -----
From: "Mark Graalman WB8JKR" <wb8jkr at JUNO.COM>
To: <HEATH at LISTSERV.TEMPE.GOV>
Sent: Friday, April 12, 2002 10:10 PM
Subject: SB-300/301 audio hum


>   Wondering if anyone else that has a SB300 or 301
> receiver has a very noticeable hum that can be heard
> in the speaker when the volume control is all the way
> down.
>  The level of the hum is not affected by the volume
> control at all, and it isn't heard when the unit is in the
> standby mode. I'm wondering if its due to the fact the
> audio tube is right next to the power transformer.
>
> Mark  WB8JKR
>
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