Topband: 160 Meter Propagation

[Tom Rauch]

> paths in the opposite direction.  You can think about that the next time
> you call a 9V and he does not respond to your call.  It's not a matter of
> attitude, just latitude, GEOMAGNETIC latitude.

What I always worry about is the noise level on the other end. A 
receiver in the middle of city like Singapore won't have the same 
noise floor as one in a rural area. The difference can be 20 dB or 
even more. 

Over the years, my experience indicates propagation is always as 
near as I can tell reciprocal. Any differences are always explained 
by looking at noise and ERP at each end. 

I certainly can't say one way propagation does not exist, just that 
I've never seen evidence of it.  I can't think of a case where the 
systems at each end are identical in noise and ERP and the path 
has only gone "one way".

Peter (9V1PC) and I exchanged identical reports because he has 
very low power and high noise, and I have high power and very low 
noise. 

The JA's and I hear each other in a given ratio (allowing for noise 
changes) as do the Europeans, and the same is true for the ZL's 
and the VK's and EA8's. People on the equator simply do not hear 
well because of noise, even though propagation to and from them is 
good.

73, Tom W8JI
w8ji@contesting.com


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