My only comment is, first of all I am not an engineer and I am not savvy always on the ins and outs of antennas, but my gut feeling is that a "L" network tuner is the better for all circumstances than a "T" network tuner.
Paul Gates K1 #0231 KX1 #1186 XG1 [EMAIL PROTECTED] ----- Original Message ----- From: "Darrell Bellerive" <[EMAIL PROTECTED]> To: <elecraft@mailman.qth.net> Sent: Monday, August 08, 2005 10:49 PM Subject: Re: [Elecraft] ATU efficiency and the Elecraft T1 > On August 8, 2005 07:30 pm, Ron D'Eau Claire wrote: > > Many Hams try to use lengths other than 1/2 wave for the radiator and > > 1/4 > > wave for the feeders. When you do that, all bets are off. It's like any > > "non-resonant" doublet or end-fed wire. They can work well, but you must > > have a matching network that can handle some potentially extreme > > impedances. Actually at any but the exact lengths for a proper Zepp, the > > feeder will radiate as much as the antenna. That's why non-resonant > > antennas fed with open wire line are usually center fed (so-called > > doublets). Such center fed arrangements hold decent balance regardless > > of > > frequency. > > Even with a center fed multiband doublet, a balun would be presented with > an > extreme set of impedances. I would suspect that on some bands or > frequencies > the whole antenna system would be quite inefficient. But as QRPer's have > proved it doesn't take much power to make contacts. A 100 watts into an > antenna system that is only 5% efficient is still 5 watts ERP. Combine > that > with an antenna that is long in terms of wavelengths and the nulls and > peaks > of the lobes will be substantial. > > Perhaps I am way behind the times, but I still think that a link coupled > balanced tuner is the proper way to feed a balanced antenna, whether > center > fed or end fed. Modern L or T antenna tuners with a balun on the output > may > be easier and cheaper to build, but just don't seem to be designed for the > multiband balanced antennas. > > -- > Darrell Bellerive > Amateur Radio Stations VA7TO and VE7CLA > Grand Forks, British Columbia, Canada > _______________________________________________ > 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 > _______________________________________________ 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
