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 > > >
