Audio hum

[N8NM]

Hi gang!

I'm finising up an overhaul of an RCA 14S7072. It's been recapped (paper and electrolytic), aligned, and overall is working great, but there's one thing nagging at me: When watching scenes with a lot of "contrast", I'll get a faint buzz in the audio. I'm reasonably certain that it's a stray signal being picked up early in the AF, before the volume control.

I can remember having other TVs that did the same thing back when I was younger beat-up old late 50's TVs were all I could afford, so, before I go digging into this, I wonder if it's normal (lack of shielding) or symptomatic of something going bad?

It's hardly noticable except when I use the DTV converter box to control the audio gain; you really have to pay attention to hear it when using the volume control on the set.

As you can probably tell, this is the first vintage TV I've restored. It's been a fun project!

If the consensus is that it's normal, I'm going to button this puppy up and enjoy it until it warms up enough to strip and respray the cabinet.

Thanks!

Steve