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
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