> Bill,
>
> In my experience, "one-way propagation" is primarily a result
> of large differences in the noise and interference environments
> on each end of a propagation path. This is a very common
> phenomenon when one end of a 160, 80 or 40 meter path is in
> full daylight and the other end is in full darkenss.
>
> On the daylight end of a 160, 80 and 40 meter path, the D layer
> significantly attenuates atmospheric noise and adjacent
> frequencies are not typically occupied by strong signals. On the
> full darkness end of the path, atmospheric noise is significantly
> elevated and nearby frequencies are often occupied by very
> strong signals.
>
> 73!
> Frank
> W3LPL
Excellent point Frank.
73 Tony KT2Q
>
>
>
> ---- Original message ----
>>Date: Mon, 3 Oct 2005 07:09:22 -0500
>>From: "Bill Jackson" <k9rz@radiks.net>
>>Subject: [TowerTalk] K7C - One-Way Propagation?
>>To: <towertalk@contesting.com>
>>
>>Towertalk Gang,
>>
>>Here is an excerpt from one of the recent K7C dx'pedition
> bulletins, regarding poor signal quality they appear to be
> experiencing on their end:
>>
>>"Let's start with a technical consideration of which you should
> be aware. As you already know, we are using vertically-
> polarized antennas very, very close to salt water and with large
> radial fields. This makes our signal launch angle very, very low -
> quite a bit lower than most horizontally-polarized antennas on
> dry land. As a result, the K7C signal has been reported to be
> very loud on the receiving end. This doesn't mean, however,
> that you are just as loud here. All it takes is a couple of
> extra "hops" from a higher launch angle and your signal will
> change from an easy-to-work S5 to being undetectable. The
> K7C team has observed a number of occasions when it is
> obvious that you can hear K7C easily, but on our end the pileup
> is only an unworkable S-1 grumble. This is most pronounced at
> the beginning and end of an opening so you may be hearing us
> long before or after we can hear you. Marginal openings on the
> paths to Europe, the Middle East and Northern Africa may be enti
>> rely "one-way" - incredibly frustrating for you to have K7C be
> as clear as bell, but not hearing the most important DXer of all -
> you."
>>
>>Does this explanation make sense? I would think that an
> antenna with a high angle of radiation on transmit would also
> favor signals with high arriving angles on receive. The amount
> of signal attenuation on a signal arriving at a low angle at the
> station with the antenna transmitting with a high angle of
> radiation should be equally diminished. Therefore the station
> with the horizontal antenna over dry land should have trouble
> hearing hearing K7C as well.
>>
>>What am I missing here?
>>
>>Even though I have managed to work them on both 80 and
> 40m, they have never had what I would call a LOUD signal,
> compared to what I often hear from KH6 land.
>>
>>73 de Bill
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
> any questions and ask for Sherman, W2FLA.
>
> _______________________________________________
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>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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