I love this idea, but there's one problem, though. I only have one coax line leading out of the shack. It runs from the Palstar (or it could run from the KPA-1500) to the input of my antenna switch. I have 5 antennas connected off that--three Yagis, and the 80m vee off the tower, and a 160 inverted-L in the back-40.
Antenna-2 on the K3s is my 6m antenna, and if I take the Palstar out of line, how do I feed the vee separately? My 80m vee is also at about a 120 degree angle, about 65' at the apex, and it plays REALLY well to Europe, the Pacific and North America. It doesn't do squat to Asia, unfortunately. - pjd -----Original Message----- From: [email protected] <[email protected]> On Behalf Of Don Wilhelm Sent: Thursday, March 14, 2019 10:59 AM To: [email protected] Subject: Re: [Elecraft] KPA-1500 tuner questions That is the antenna I use on 80 meters. It has a double-humped SWR response and stays below 2:1 between 3500 and 3900kHz. Up at 4000kHz it is a little higher than 3:1. The 1/4 wave 75 ohm section is a transmission line transformer. The 1/2 wave 50 ohm line repeats the impedance at the antenna feedpoint. Mine is an inverted Vee with a 120 degree angle at the apex. Since the 75 ohm section is 1/2 wavelength on 40 meters, the same feedline can be used on 40. So I also have two radiator wires for at right angles to the 80 meter radiator. Being at right angles, there is no interaction. 73, Don W3FPR On 3/14/2019 2:51 AM, Jim Brown wrote: > > Here's a VERY old solution that W6NL has taught to his EE classes. > When I asked him about it, he says it's not his original idea, far > older than him. > > Tune your 80M dipole to 3675 kHz, feed it with a half-wave of 50 ohm > coax starting at the antenna, then a quarter wave of 75 ohm line. Line > lengths are at 3675 kHz. Add 50 ohm coax as needed to reach the shack, > or coil up the excess if those two lengths are too long. The result > will be SWR below 2:1 from 3500 kHz to 3900 kHz. With good RG213 and > RG11, Line loss is about 0.5 dB at the resonant point and about 0.7 dB > at the limits. > > If you want to do some engineering, you can probably tame that 40M > antenna too. Here's a tutorial applications note. > http://k9yc.com/PacificonSmithChart.pdf > > 73, Jim K9YC ______________________________________________________________ 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 ______________________________________________________________ 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
