Are you sure your ladder line is 200-300 Ω? My calculations say that 12 AWG conductors 12 inches apart makes 680 Ω line.
wunder K6WRU Walter Underwood CM87wj http://observer.wunderwood.org/ (my blog) > On Oct 28, 2021, at 2:47 PM, Joe Subich, W4TV <[email protected]> wrote: > > > Your 130' dipole will be damn near impossible to feed on 40 meters as > the center is very high impedance. You would be better served to > hang a parallel dipole (33' per side) under the 65' wires and use > RG213/RG8 for the vertical section. > > The additional 33' wires will give you marginally more top loading > and the coax will work just as well for the vertical element since > you are shorting it top and bottom. While you're at it, push the > feeedpoint up to 50 feet ... more vertical for 160/630m and better > performance for the dipole on 80/40. > > 73, > > ... Joe, W4TV > > > On 2021-10-28 5:23 PM, Ed Cole wrote: >> I am redesigning my 40/80/160/630m antennas. >> A year ago the tower I was supporting my 630m Invert-L was damaged by wind >> and taken down. Replacement tower is shorter so not suitable end wire >> support for HF antenna. >> I decided to repurpose my 80/40m dual dipole into a based-loaded 40-foot >> vertical using the 80 & 40m wires for top hat loading on 160/630m. To do >> that I purpose to run 40-foot of ladder-line vertical and either load the >> bottom using a balun for 80/40m or short the ladder line for the loaded >> vertical. >> http://www.kl7uw.com/630mTee.jpg >> My question is what balun to use for 80/40m. ladder line is 200-300 ohm >> whereas the dipoles are near 50-ohm. Should I use a 9:1 balun or would my >> original 1:1 balun work? Tuners will be in the shack (KXAT at 100w; Drake >> MN-2000 at 1200w). RG-13 coax to base of ladder-line. >> I have a couple vac-relays to short the ladder-line and connect the loading >> coil for 160/630m. >> Thanks, Ed - KL7UW > > > ______________________________________________________________ > 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]
