HI Lou,
I've lived in two apartments in Sacramento.
One from 1990 until 2001 and the second one from 2001 until 2007.
I'm now back in my original apartment where lived from 1990 until 2001.
I've had these problems in both locations.
In fact in the second apartment I had no HF gear at all.
I got some good tips from Steve Horst so may try my 20 meter dipoles again
and see what I can do.
73,
Eric
KU3I