Rick, what are the ball park figured on the coil diameter???? I'm guessing 5 or so inches across is a good place to start
Paul. N0AH Sent with AquaMail for Android http://www.aqua-mail.com On November 1, 2017 11:25:42 AM "Richard (Rick) Karlquist" <rich...@karlquist.com> wrote: > You need +j34 ohms in parallel with your coax coming in. > This is about 3 microhenries. This would be around 6 > turns on your coil if the turns are spaced a wire > diameter. IOW, tap the coax 6 turns from the grounded end. > Then tap the antenna to whatever tunes to 1.83 MHz. > > Rick N6RK > > On 11/1/2017 9:54 AM, MR TREVOR DUNNE wrote: >> >> Hi All >> >> >> >> I finally got the vertical up and running, problem I have now is I can't >> find a low SWR on the coil, the best I can get is about 2.8:1 no matter >> where I tap the coil that's the best SWR, I can move that point up and down >> the band by moving the tap but the SWR stays the same, >> >> My current set up is about 55ft vertical I have 2 loading wires in a T >> shape, wires are 50ft either side of the vertical and the are pretty level >> and in line, >> >> I have 38 radials averaging about 45-60ft long, I will add more when time >> allows but don't the make the SWR worse ?? >> >> With no coil I get resonance at 2.12mhz with R=16 X=2 on my MFJ269, >> >> The coil is 25ft of 5mm copper brake pipe in a 4" diameter, the coil is >> attached to base of the vertical and the other end is grounded, >> >> Any pointers on what I can do to get a better match, >> >> Thanks >> Trevor >> EI2GLB >> _________________ >> Topband Reflector Archives - >> https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.contesting.com%2F_topband&data=02%7C01%7CK7OX%40msn.com%7C032f93683a6241271c8808d5214d934d%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636451539420438619&sdata=X6KDWuh9loRub4Ciq0nWsv1q%2BSrCmiOXAtxbHo621uk%3D&reserved=0 >> >> > _________________ > Topband Reflector Archives - > https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.contesting.com%2F_topband&data=02%7C01%7CK7OX%40msn.com%7C032f93683a6241271c8808d5214d934d%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636451539420438619&sdata=X6KDWuh9loRub4Ciq0nWsv1q%2BSrCmiOXAtxbHo621uk%3D&reserved=0 _________________ Topband Reflector Archives - http://www.contesting.com/_topband