Greetings,

I am in a particularly sticky situation with one of my two meter repeaters in 
Lakewood, WA (Tacoma). I have generally great coverage, however there is a very 
annoying problem with multipath and raspy signals in a large portion of my 
coverage area. Since the Puget Sound area of Western Washington is very hilly 
and mountainous, multipath is very damaging to all forms of VHF communication.

Over the years I have read about folks employing circular polarization to 
overcome fading, nulls, multipath, etc. There is so  very little written about 
this topic in amateur circles so I thought I'd bring it up here and see what I 
could come up with.

In the 80's there was a amateur radio repeater book by a fellow, Pasternak I 
believe, that took two gamma match style Cuschcraft Four Pole antennas, 
combined them, and did some magic with phasing lines to end up with a four bay 
circularly polarized repeater antenna.  Unfortunately the description leaves 
much to be desired, at least for me, so I never built one. If he would have 
included specifics on phasing line lengths, cable types, etc, the job would 
have been a whole lot easier. Has anyone actually gone circular with Cushcraft 
Four Poles, and if so, could you please share it with me and/or this group?

I have done some inquiring to commercial companies about a custom built two 
meter four bay circularly polarized array, but that is entirely out of the 
question. They want thousands of dollars. There must be an easier (and cheaper) 
way.

Similarly, is anyone in this group running circular polarization on your 
amateur repeater(s), and if so, could you please share the details in a manner 
that could be duplicated without a lot of guess work? 

I know that I could easily solve my multipath problem by installing one or more 
remote receivers, however I would like to keep that as a last resort and shoot 
for a circularly polarized antenna system at the main repeater site.  I do 
understand that there is approximately 3 db of loss as a result of this, but 
that is quite acceptable. The dividends would greatly outweigh the down side.

Thanks for any constructive ideas, suggestions, links, etc, that you might be 
willing to share concerning this situation.

Best regards,

Gary, K7EK

Personal Web Page:  www.k7ek.net



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