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We have spent much time over the last two years looking into replacement rods or tubing for the EF type of loading. Several obstacles were encountered, including the UPS box size limitation and the need for flexing of the tube. After much investigation, we decided it was just not practical. 40 meter and 80 meter antennas are typically installed close to the ground in terms of wavelength. Because of this proximity the need for some final adjustment is present for ANY type of loaded or smaller element and to a lesser extent for full size elements. We do not feel that a "fixed" factory adjustment would render the best performance, therefore our elements are easily adjustable. If you are a purist, I suggest adjustment of the elements before mounting to the boom. Take the driver up the tower about 30' and bring the resonance, as indicated by a dip in the VSWR, to the point where needed. The parasitic element can then be adjusted in the same manner by resonating the element at a frequency near 6900 kHz ---- the actual frequency is model dependent. Of course I have the exact frequency for each model when needed. After both elements have been resonated this way, the antenna can then be assembled knowing the adjustments are sound and will need no additional changes. The ability to adjust frequency of our elements is a real plus as the affects of nearby ground and other objects can be quite problematical. 73 Natan W6XR Force 12 East Ithaca, NY FN12sk ----- Original Message ----- From: "Pete Smith" <n4zr@contesting.com> To: <force12talk@qth.com> Sent: Thursday, April 20, 2000 7:45 AM Subject: [Force 12 Talk] EF series retrofit possible? > Any possibility of a retrofit kit for the EF series yagi elements to > replace the wire loading with pre-cut rigid rods, a la the C-3SS and the N > series? I for one, would be a ready customer -- I lack the $ and tower > capacity for an N-series 40m yagi, but think my EF-240S would be much > improved. Cut-and-try on elements 9 feet from the mast is a real pain. > > 73, Pete Smith N4ZR > n4zr@contesting.com > > Don't forget to update your entry on the World Contest Station Database, > now at http://www.contesting.com/stationdatabase.htm > > > -------------------------------------------- > Force12Talk mailing list provided as a service by Force 12 Antennas, Inc. > Force 12 Web site: http://www.qth.com/force12 > > Submissions: send to Force12Talk@qth.com > To unsubscribe: send a blank e-mail to Force12Talk-leave@qth.com > Force12Talk Message Archive: http://www.qth.com/force12/list/force12talk > 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 Submissions: send to Force12Talk@qth.com To unsubscribe: send a blank e-mail to Force12Talk-leave@qth.com Force12Talk Message Archive: http://www.qth.com/force12/list/force12talk For problems with the list, contact force12@qth.com |
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