Topband: What do you use as a "Run" antenna?

Tom Rauch w8ji at
Wed Feb 28 06:46:23 EST 2007

I never said it was a difference in absorption.

I said it was because noise levels and QRM levels are higher 
at the dark location. The D layer attenuates the QRM and 
noise at the daylight spot the same as it attenuates the 
desired signal, but the guy listening at the dark location 
has all that unattenuated noise and QRM from other 

Picture this.

You are station B in daylight receiving station A who is in 
darkness. At your location, station A is attenuated by the 
daylight D layer the same as all the distant noise and QRM.

The fellow at station A (in darkness) is faced with noise 
and QRM that is NOT attenuated from other directions, but 
your signal from out of the daylight is.

That is what makes it easy in late daylight to hear distant 
stations out of a dark area while they can't hear you.

For example during afternoon daylight my noise floor is 
about 10dB or so less than at dark. I can hear Europeans 
very well but there is little hope they can hear me. As it 
gets dark, the noise and signals here go up together because 
the D layer starts to fade, the noise in Europe doesn't get 
any worse, and now when I call I'm ten dB stronger and they 
can hear me.

The reverse effect occurs after my sunrise. I can hear west 
coast stations very well even at 10-11 AM. When I call them, 
they don't hear me nearly as well. This is because they have 
all the darkness noise and QRM while the darkness QRM and 
noise is attenuated here almost the same as their signals. 
They don't lose S/N as fast here as I do there at my 

A second factor is people aren't normally listening into 
daylight as much as they are listening towards dark paths. 
This is especially true in contests where there might be 
hundreds of workable signals from the dark path while there 
are only occasional signals from the daylight areas.

IMO that is what causes the frustration. I learned long ago 
to not bother calling Europeans that are readable at 1-3PM 
local here. They are closer to dark and have higher noise. I 
am in daylight and have virtually no propagated or local 

By the way, this noise problem  in not escapable. Noise on 
low bands always comes in from a great distance, even in 
winter. The only exception is if you have dominant local 
noise that masks distant noise. What we attribute to as "one 
way propagation" is almost always the fact that noise level 
is too high at one end of the path.

73 Tom

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