[PCR-1000] HF reception

[David Carr]

I just got my PCR1000 back from Icom for repair.  I was monitoring 20 
meters from downtown Houston today but noticed some strange effects.  
Using my 20m dipole I hear lots of strong tones (~500hz wide)  in the 
band and it just so happens that many of them seem to exist right on top 
of SSB stations.  This makes many stations uncopyable.  Some stations 
are unaffected but I can't help but wonder what is causing this effect.  
Is this the radio's doing (adjacent overload/something broken) or is 
there just a lot of QRM here that just happens to be centered on various 
stations?  The latter seems unlikely to me.

Thanks for your ideas,
David Carr