"Dick Green". wrote:>
> So, I went back and forth, lengthening the antenna until the transceiver
> reported minimum SWR at 7.150. At this point, however, the MFJ reported
> minimum SWR was ocurring at 7.300! I ignored the MFJ's results and have been
> operating happily on 40M ever since (the antenna is very broad; the SWR
> hardly budges across the entire band.)
Hi Dick. I have a three element vertical aray here, and the run of coax
to each element is about 50 feet and I do the switching and phasing
inside the shack. I have adjusted the antennas at the base of the
vertials for as close to 1 to 1 as I can get. Usually about 1.6 to 1.8 to
1. I have an extensive radial field under all three also the 160 meter
inverted L. They are just laying on the ground-all different lengths. I
tied the hub of each antenna together so that each antenna is using all
the radials. It works very well. I have found that the length of coax
going from the swr bridge to the phase box makes a difference on the swr.
You might experiment with adding a length of coax from the swr meter to
the line going to your antennas. I've found that makes a big difference.
I have a switch box in the shack to switch the antennas and I
experimented with the length of the coax going from the box to the swr
meter till I got it the same as at the base of the antenna. You want to
be sure the coax from each antenna is the same length though. I think if
I put some kind of balun at the base of the vertical, it might keep the
swr from changing. Another thing I did was make a coil choke right where
the coax came into the shack. I had some problems with rf getting into
stuff in the shack. After I wound the chokes, I didn't have any more
problems. My antenna is swichable to 6 directions, and it sure has made
40 meter operating more fun. Good luck and you will surely enjoy those
antennas. Merry Christmas
Tom W7WHY
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