Just to clarify: I'm referring to *end-fed* antennas that are a multiple of 1/2-wave. The feedpoint impedance of such antennas is extremely high, something like 3-6 Kohms.
A 1/2-wave dipole or inverted V, fed in the middle, will typically be 50-75 ohms. Wayne N6KR On Apr 24, 2012, at 1:08 PM, Wayne Burdick wrote: > 67' is very close to a half-wave on 40 m and a full-wave on 20 m. In > theory the SWR should be insanely high, so I'm surprised the K1 ATU > handled it on 20 m. Even if it did, the losses would be very high. > Best to use lengths that aren't close to a multiple of a half-wave on > any target band. > > Wayne > N6KR > > On Apr 24, 2012, at 10:11 AM, Niel Wiegand wrote: > >> Robert, >> >> I've found that the KX3 ATU loads up a 58' endfed wire just fine on >> all >> bands, but it can't load up everything. The 67' endfed wire I have >> (which, in theory, is very tough to load up) could be loaded up on >> 20 >> with the K1 ATU. The KX3 ATU can not handle it. >> >> So, for your loop, depending on the size, you may or may not have >> trouble depending on the length. For a closed loop I believe you >> want to >> avoid odd multiples of half wave lengths. If the possible length you >> have is pretty inflexible and the KX3 ATU can't handle it you can try >> inserting an insulator half way around making it an open loop. >> >> 73, >> Niel - W0VLZ >> KX3 #43 >> >>> Message: 21 >>> Date: Tue, 24 Apr 2012 12:50:28 +0000 >>> From:va3...@gmail.com >>> Subject: [Elecraft] KX3 ATU >>> To: "Elecraft"<elecraft@mailman.qth.net> >>> >>> >>> Does anyone know what the capability/efficiency of the internal ATU >>> is? >>> >>> Not talking about the wattage (its up to 20 I believe) but the >>> tuning the SWR/range >>> >>> Looking at deploying a random wire/loop so I am wondering if I need >>> a separate ATU or can the internal unit handle the range? >>> Thanks >>> Robert >>> >>> a 'kosher' ham >>> Sent from my BlackBerry device >> >> ______________________________________________________________ >> 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 > > ______________________________________________________________ > 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 ______________________________________________________________ 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
