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Old 02-20-2017, 10:51 PM
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Findm-Keepm Findm-Keepm is offline
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Quote:
Originally Posted by old_coot88 View Post
I never seen a radio of that vintage that didn't have some degree of hum, particularly ones using direct-filament tubes (e.g., 26, 71A etc) with the filaments run on AC. Some had a 'hum balance' control but the hum was always there anyway.
The winding just above the rectifier filament winding has a hum filter - the center tapped 15-ohm resistor. Check it as well - bad, and it could introduce more hum.
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