If I had a doublet I would seriously consider feeding it like the W5DXP which uses switched ladder line for matching . Looks cheap, low loss and easy to do: any residual mismatch should be compensated by the K2/K3 auto-matching system.
http://www.w5dxp.com/notuner.htm David G3UNA > > From: "Geoffrey Mackenzie-Kennedy" <[EMAIL PROTECTED]> > Date: 2007/09/10 Mon AM 05:09:13 BST > To: "Ron D'Eau Claire" <[EMAIL PROTECTED]> > CC: Elecraft Discussion List <elecraft@mailman.qth.net> > Subject: Re: [Elecraft] Balanced AT > > Ron AC7AC wrote: > > > Another issue with a balanced AT is that they tend to be used in multiband > systems fed with open wire line where high SWRs are expected. High SWRs mean > very, very high RF voltages at a current "loop", demanding relays, etc., > that can safely deal with thousands of volts of RF at any power level much > above QRP. > > --------------------------------------------------------------- > > A timely warning Ron. This is one reason why commercial remote antenna > matching units designed to handle such high voltages and / or currents > without going up in smoke tend to be expensive. Fortunately for those of us > who homebrewed in ancient times suitable vacuum relays and and Mil Spec wide > spaced air variable capacitors were available at bargin basement prices. > > 73, > Geoff > GM4ESD > > > > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > ----------------------------------------- Email sent from www.virginmedia.com/email Virus-checked using McAfee(R) Software and scanned for spam _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
