Jim, my antenna is somewhat unusual. It is a Sommer XP-708, where the hardware added to enable 40m is very minimal: just a coil hooked up between two points on an antenna whose dimensions say "20m and up". Given that each antenna element is appropriate for 20m or shorter wavelength, and the boom is no longer than the elements, the narrow bandwidth on 40 is not surprising. Also, the antenna has no directivity at all on 40. One might wonder if this antenna might be a compromise in other respects, but the performance in actual use has always been a positive surprise to me. For the cost of adding 40m to the basic design, I would say that it is a great value.
73, Erik K7TV -----Original Message----- From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> On Behalf Of Jim Brown Sent: Tuesday, October 16, 2018 10:58 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] Looking at KPA1500 On 10/16/2018 10:24 PM, Erik Basilier wrote: > My main 40m antenna meets that requirement over a significant portion > of the band, but at band edges swr can be 4.5:1 or so. Hmmm. 40M is not very wide (only 4.2%, as compared to 80M which is 14.3%). What kind of antenna is it? Simple antennas without traps or loading coils like resonant dipoles and verticals typically cover 40M with SWR below 2:1 if tuned to the center of the band. 80M is the tough one, but can be tamed with some transmission line and or stub tricks. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to ebasil...@cox.net ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
