[n7cl@toontown.mmsi.com: Re: [TowerTalk] A Question of GAIN]

[w8ji.tom]

Hi Tom,

In an earlier post, I specifically ruled out the case of direct wave
propagation where a linear polarity radiator can be effectively used with a
circular polarized radiator at the other end to reduce some types of
fading, or vice versa.
I probably should always keep repeating that qualification.

FM stations do this in the reverse mode, using a circular polarized
transmitting antenna to reduce fade sensitivity of linear polarized
receiving antennas.

Ground wave or direct wave propagation is a much different situation than
HF communications via sky wave. While we find hundreds and thousands of VHF
broadcast stations using circular polarized transmitting antennas, we
almost certainly won't find a case of well engineered professional HF
transmitting doing the same. Not one shortwave broadcast transmitter, not
one VOA site, no matter how much money they have to spend on large complex
antennas. 

73 Tom

> My notes are buried somewhere since we moved to this new location;
otherwise, I 
> could provide additional information about the physical distance between
the 
> nulls. From memory, effective distances between antennas for spacial
diversity 
> was much less than anticipated.
> 
> Hope this is useful.
> 
> Have a great day & 73,
>                 Tom Schiller, N6BT


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