I use an EFHW on 80-10, no dedicated counterpoise, no coax length rqmts. However, NEC2 doesn't like a source at the open end of a wire so to model it, I have to put some counterpoise on the wire. Length not critical, 5-10 ft is fine.
73, Fred K6DGW David Gilbert <[email protected]> wrote: > >I'm confused why an EFHW should need a counterpoise. If it needs a >counterpoise it isn't actually acting like an EFHW. If it needs a >counterpoise that means there isn't enough choking impedance at the >feedpoint, and it means that the feedline is radiating with the >counterpoise acting as ... well, a counterpoise. > >Manufacturers state a minimum length feedline simply to have the >feedline losses help swamp out SWR variations along the line, and of >course to marginally lower the SWR. > >Dave >AB7E > > >On 7/14/2016 1:03 PM, Don Wilhelm wrote: >> Andy, >> >> What happens if you connect to a dummy load? Does the KX2 tune it >> properly? >> If so, then you know the KX2 is operating into a 50 ohm load OK. >> >> Do you have an antenna analyzer? If so, then connect it to the >> antenna feedline and look at the impedance - both real and reactive - >> as well as the SWR. >> That will tell you whether the antenna is troublesome. >> >> You specifically said an EFHW - that should be a resonant antenna. If >> instead you have a random length wire (not a halfwave), and what is >> the matching device? >> Many EFHW antennas need a counterpoise to work - that is why many >> manufacturers state a *minimum* length feedline. >> >> If the problem is *not* the antenna, contact Elecraft support. >> >> 73, >> Don W3FPR >> >> On 7/14/2016 2:40 PM, Andy Clift wrote: >>> Just received my KX2, but unable to get it to tune an EFHW wire. I’ve >>> tried a home made one and then tried a SOTABEAMS MultiBander that >>> I’ve used successfully with an FT-857. I’ve checked the continuity in >>> the wire and also the continuity in the KX2 between the BNC connector >>> and where the wire connects inside the KX2 (as I removed this to fit >>> the end panels). Battery is at over 11v. Any ideas please? >>> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[email protected] >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to [email protected] >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [email protected] > >______________________________________________________________ >Elecraft mailing list >Home: http://mailman.qth.net/mailman/listinfo/elecraft >Help: http://mailman.qth.net/mmfaq.htm >Post: mailto:[email protected] > >This list hosted by: http://www.qsl.net >Please help support this email list: http://www.qsl.net/donate.html >Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
