On 13 Jun, 16:32, Buck wrote:
On Wed, 13 Jun 2007 10:38:04 -0700, Jim Lux
wrote:

Buck wrote:
On Mon, 11 Jun 2007 22:00:14 -0700, "Alfred Lorona"
wrote:

Is there a site that explores/explains the latest theories on one way
propagation? The ARRL antenna book is not much help on the subject.

tnx, AL

One way Propagation: The cause of one-way propagation is a station who
uses power to overcome antenna losses. the station can be heard but
cannot hear.

or they are ignoring stations they don't want to talk to....



perhaps on VHF and higher where receiver noise dominates. On lower
frequencies, where atmospheric noise dominates, one could tolerate quite
a bit of loss in the antenna/feedline and still "hear" exactly the same,
since the SNR at the antenna dominates the overall situation.

A nice practical example, in use in many HF commercial, government, and
utility type stations, would be the use of an antenna that has been
broadbanded by use of lossy elements (e.g. the terminated folded dipole
sorts of things). You might take a 6-8 dB hit in the antenna loss, which
you make up by jacking up the Tx power by 6-8 dB, but you also don't
have to worry about tuners, etc. This would be particularly useful if
you were doing ALE or frequency hopping.

and actually, my original comment was tounge-in-cheek. I sent before
realizing I hadn't added the wink.

--
73 for now
Buck, N4PGW

www.lumpuckeroo.com

"Small - broadband - efficient: pick any two."

Surprises me that nobody has made reference to dissimilar antennas
as possible contributors, especially if one was dual polarised.
Also have heard that one station had to turn his antenna some
40 degrees to achieve parity. Then there is the situation
where local terrain( knife edge cliff top) provides one way
transmission So I am inclined to say that parity is achieved
if conditions at both ends are the same or equivalent