Thanks to all that replied. I appreciate your input. I'm still looking for
answers, but may be onto something. I have emailed Bill Pasternak, the author
of that Cushcraft 4-pole conversion article. I re-read his original article and
may have figured out what I must do. That, plus any additional input from Bill,
should hopefully help me to complete the project.
I will post again later if I have any success.
Best regards,
Gary, K7EK
Personal Web Page: www.k7ek.net
--- In Repeater-Builder@yahoogroups.com, Gary - K7EK gary.k...@... wrote:
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
