Low level tone on SSB receive in Omni V

[km4dt@ix.netcom.com (William A. Childress)]

I have a tone (approximately 1000 Hz) in the receive audio of my Omni V.
It's very low level, but it's still annoying. I can remove it by setting 
the notch filter at the 12 O'clock position, but I'd prefer to remove 
this without depending on the notch. Is this a common problem on the 
Omni V.  If not, then does anyone have a clue as to the likely source.

<Alan>