early on the antenna would help define the operating frequency spark made RF everywhere and the tank and antenna coupled the RF to the operating frequency
Bob K3DJC On Fri, 5 Aug 2016 18:41:57 -0400 "Charlie T, K3ICH" <[email protected]> writes: > I'm curious as to when the concept of a ½ λ dipole became the norm? > > In other words, the idea of the current distribution as exists on a > dipole. > > Early pictures of typical ham antennas looked more like a set of > parallel > clothesline wires. > > What I gather from reading early articles, it seemed that the more > wire you > had in the air, the better it would "capture" (and radiate) the > signals. > > Feel free to reply directly if you don't want to clutter the forum. > > (k3ich at arrl dot net) > > 73, Charlie k3ICH > > > > -----Original Message----- > From: Elecraft [mailto:[email protected]] On Behalf > Of Phil > Wheeler > Sent: Friday, August 05, 2016 10:58 AM > To: [email protected] > Subject: Re: [Elecraft] OT:. G5RV's > > Alas, the poor G5RV. Now that its been flogged to death, maybe we > need a > new target -- say the Windom? > > Phil W7OX > > On 8/4/16 10:22 PM, Wes Stewart wrote: > > The tuner loss also depends on how it is adjusted. For example the > > > very popular high-pass Tee with three adjustable elements has an > > infinite number of possible combinations that will effect a match > on > > the same load Z. One of them is the lowest loss solution, all of > the > > others aren't. > > > > As I said earlier, in a letter to Dean Straw dated February 2, > 1994 I > > offered an example where the SPC tuner, then current in the > handbooks, > > could be used to match an impedance of 4.34 +j46 to 50 ohm. (I > forget > > where this came from but it was a real possibility) I assumed Qc > = > > 1000 and Ql = 300 (generous). I used Touchstone to calculate the > > minimum loss and maximum loss solutions The best case was 1.6 dB > and > > the worst case was 7.8 dB. > > > > With lower Q components, Qc = 500, Ql =200, the losses were 2.4 to > 9.5 > > dB! > > > > Wes N7WS > > > > > > On 8/4/2016 2:00 PM, Alan Bloom wrote: > >> > It's a pity that too many newcomers, as well > >> as many oldsters, are > >> > enamored by this piece of wire. > >> > >> The G4RV is definitely a compromise antenna. > >> However its advantage is that is has low-enough SWR to be easily > >> matched by most tuners on a number of bands. > >> > >> > ... the horrific losses that could be > >> incurred even > >> > with high quality tuners, > >> > >> It's true that tuner losses are the > >> manufacturers' dirty little secret. Loss is rarely specified, > partly > >> because it can be pretty bad, and partly because it is hard to > >> measure, but also because it is not constant - it depends on the > >> particular impedance being matched. > >> > >> One exception is the old Drake tuners. Their Pi-L topology makes > the > >> loss almost independent of the load impedance. If you can get it > to > >> match, you know that almost all the power is going into the feed > >> line. For example, the > >> MN-2700 that I designed when I was at Drake was specified at 0.5 > dB > >> maximum insertion loss and I did a lot of testing and tweaking to > > >> achieve that on all bands. > >> > >> Alan N1AL > > ______________________________________________________________ > 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]
