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That was done by Dan Levin with help from L.B. Cebik. NH ----- Original Message ----- From: Pete Smith <n4zr@contesting.com> To: <force12talk@qth.com> Sent: Wednesday, February 23, 2000 1:27 PM Subject: Re: [[Force 12 Talk] Why I bought my 54 F12 elements ] > At 11:37 AM 2/23/2000 -0500, Natan Huffman wrote: > >Kevin, > > > >I noticed in your post you stack a C51XR/C31XR and C3E. For practical > >purposes, the C31XR and C51XR are identical, but the C3E is not. Did you > >make any adjustments (such as length of coax to compensate for phase > >differences) or just "brute forced" the feeding of the C3E. Stacking non > >identical antennas can be challenging! Or, perhaps the C3E is not part of > >the XR stack. > > > >We are often asked about this type of scenario but just have not had the > >time to do a good analysis and develop a recommendation. > > There was a post within the last couple of months on Towertalk about this. > If I remember the particulars correctly, this person had stacked one of > your multiband antennas with the closed sleeve feed system, with a straight > yagi with split dipole feed, and used NEC-2 and lots of trial and error to > calculate the phase shift that was required to achieve pattern addition. > The number was striking, I remember -- ~ 160 degrees. He said it then > worked roughly as predicted. > > >From some other things I've read, I'm now wondering if this analysis was > good or not, since NEC-2 reportedly has trouble with modeling this type of > feed. Nonetheless, a thought. > > 73, Pete N4ZR > > Don't forget to update your entry in the World Contest Station Database > http://206.102.70.3/search.htm > > > ---------------------------------- > Force12Talk mailing list provided as a service by Force 12 Antennas, Inc. > Force 12 Web site: http://www.qth.com/force12 > > To unsubscribe, send a blank e-mail to force12talk-leave@qth.com > For problems with the list, contact force12@qth.com > > -------------------------------------------- Force12Talk mailing list provided as a service by Force 12 Antennas, Inc. Force 12 Web site: http://www.qth.com/force12 Force12Talk Message Archive: http://www.qth.com/force12/list/force12talk To unsubscribe, send a blank e-mail to force12talk-leave@qth.com For problems with the list, contact force12@qth.com |