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Old November 25th 03, 08:10 PM
Mike Coslo
 
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Mike Burch wrote:

I have recently built a J pole for 2 meters from the handbook and I was
wondering if any of you had some tuning tips.



I just put mine up this past weekend. I made a Jpole out of 3/4 inch
copper pipe. My coax is attached with copper pipe clamps. To tune, I
used a MFJ antenna analyzer, but anything you have that measures SWR
will be okay.

As I moved the clamps up or down on the antenna, I could tune the SWR &
resonance pretty easily. Biggest problem was having to walk away from
the antenna (on the roof) to keep from affecting the readings. Tuned it
for 1:1 on my favorite repeater frequency which happens to be in th
emiddle of the band, and have less than 1.5:1 at the edges. The antenna
works very well compared with the homebrew 1/4 wave ground plane I had
before.

The clamps are supposed to move up and down equally on the antenna, but
the position that gave me the best resonance and SWR hade the braided
wire clamp just a tad below the center conductor clamp, so that may be
another area for adjustment.

Seems like it would be a dead short, doesn't it?

Hope this helps!

- Mike KB3EIA -