[mod.telecom] Hum Suppression Wanted

kyle.wbst@XEROX.COM (10/02/86)

A friend has a new gift of a "Ring-On" Model TL-6630 AM/FM Clock
Radio/Telephone with built-in speaker phone feature that has a fairly
loud humming noise when using it as an ordinary phone. The sound is
similar to the noise I often hear in jumbo jets when listening to music
on the headphones (that's a 400 Hz tone, I think).

Any suggestions to solving this problem?

Thanks,

Earle.