I have an array of dipoles, some trapped, some using W9INN style chokes. I also have a tribander. But the antenna that gets used all the time is 160' doublet fed with 300 ohm line which goes into a DX Engineering 1:1 balun with short piece of RG-8 type coax coming into the house. The tuners on the K1, K2, and K3 will tune it to any band. I have experimented a great deal with fan dipoles. They certainly work. And also Off-Center fed antennas; they also work well. Loops a good too. I have a notebook with 40 years of wire antenna experiments. For me the most satisfying antenna so far is the simple doublet. It will always be the first antenna I recommend. With the great tuners in the Elecraft gear, it seems like a no-brainer.
73, Doug -- K0DXV On 4/15/2011 6:16 PM, Ron D'Eau Claire wrote: > I played with a fan dipole back in the 1960's, and played and played and > played trying to get a decent (less than 3:1) match to 50 ohm coax. Never > was happy. > > That experiment taught me the efficiency, ease and simplicity of a doublet* > fed with open wire line. Working out the process of getting the open wire > line into the shack wasn't nearly as difficult as trying to get the antenna > to present a decent match to the coax, and it was a wonderfully efficient > and effective all band antenna mounted at an "inverted V" with the apex at > 50 feet. > > BTW, my doublet was 100 feet end-to-end and worked beautifully on 160 > through 10 meters. Granted, at so close to the ground the radiation was > mostly straight up on 160 but on that band I was mostly interested in > working locals out to 100 miles or so. We had a lot of mobiles active on 160 > back then as well as fixed stations. And none of the rude nonsense so often > found on 75. > > Ron AC7AC > > *Wire fed at the center but not necessarily a "dipole" - i.e. 1/2 wavelength > long - on any band. > > -----Original Message----- > Subject: Re: [Elecraft] K2 + ATU + Loop antenna in the attic > > Alan, > > Sorry to hear about your lack of success with the fan dipoles. I have > three of them - one for 80 and 40, another for 30, 17 and 12m, and yet > another for 20, 15, and 10. They work very well. > > My "secrets" - space the wires for each band away from one another - my > 80 and 40 antennas are at right angles to each other, so there is little > of any interaction. The other two have the wires spaced about 1 foot > apart using CPVC pipe with holes drilled in them (wires through the > holes) to maintain the spacing. PVC would work too, but is heavier). > > The antennas do interact, so plan ahead, you will have to do some "cut > and try" pruning. Tune the lowest band or resonance first, and then the > next band higher in frequency. Trying it the other "way 'round" is an > exercise in futility (been there, done that, and have the scars). > > I usually consider 3 bands on one feedline the limit of my patience, but > this last weekend I helped a friend construct an antenna with 4 wires - > 80, 40, 20, and 10 meters. It was a bit of a pain to tune, but it > worked out well. Cut the wires at least 10% long and prune as required. > > One other point - do not use separate wires for bands that are close to > the 3rd harmonic of another band - in other words, for HF, do not put a > 30 meter radiator on a feedline that contains an 80 meter wire, and do > not put a 15 meter wire on a feedline that also has a 40 meter wire. > The lower band antenna may be usable on the 3rd harmonic (likely with a > tuner), but trying to combine those two wires will result in even more > frustration. > > 73, > Don W3FPR > > On 4/15/2011 6:15 PM, Alan D. Wilcox wrote: >> FWIW, see my fan antenna at >> http://wilcoxengineering.com/projects/amateur-projects/39-fan-dipole >> A bright idea that didn't work out so well! >> >> Cheers, Alan >> >> Alan D. Wilcox, W3DVX (K2-5373, K3-40) >> > ______________________________________________________________ > 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
