On Jan 19, 3:38*pm, Roy Lewallen wrote:
wrote:

Yes, KHz, sorry.

The noise goes up several fold when I pass underneath bridges/pass big
trucks, etc. Does this suggest that the noise is from other
frequencies?

No. It means that the noise is coming from outside your car. Your
antenna and radio can't tell the difference between this noise and the
desired signal, so improving your antenna or increasing your receiver's
sensitivity will simply increase the signal and noise in the same
proportion. And because it's not coming from your own car, there's no
way for you to reduce the noise. In other words, there's really nothing
you can do to improve the S/N ratio in the presence of that noise.

Roy Lewallen, W7EL

increase the signal and noise in the same proportion.
Is there anyway to "filter" the 810 frequency somehow?