Topband: Carriers-QRM

[wb6tza@socal.rr.com]

Yosi posted a plea not to use frequencies zero beat with BCI 
products.   This applies world wide, and is an especially prevalent issue 
in the US where there so many AM broadcast stations.

US broadcast station products fall on the 10 KHz frequencies, most world 
wide stations fall on 9 KHz frequencies.

to summarize

ALL stations looking to be heard well should avoid being exactly on "round" 
KHz frequencies - any as a rule of thumb, but these in particular.

Specifically, avoid
1809.0
1810.0
1818.0
1820.0
1826.0
1830.0
1832.0
1836.0
1840.0
1845.0
1850.0

The list continues. and there are others within this block

I have noted that it seems particularly common for EU stations to pick 
1820.000 or 1830.000 to CQ on -  This is why your QSO rate is lower than it 
could be.  These are VERY bad frequencies in the US.  Heard one just tonite 
on 1820.000. BAD!.

If you have a choice, using the half KHz frequencies generally seems to 
work well.  If you must be close to one of the frequencies above, try to be 
at least 100Hz off.  Generally, that is just barely enough except under the 
weakest signal conditions.

Please try to share this information, especially with the less experienced 
topbanders in your region - this is not the kind of information that should 
be an operating "secret".

73

Robin Critchell,
WA6CDR-XZ0A et al
see you from N5IA CQ160


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