Dan Richardson k6mheatadelphia wrote:
On Mon, 20 Mar 2006 08:12:51 -0700, jimbo wrote:


OK, I have a new 2 meter j-pole antenna installed in my 3rd floor
attic. I have 50 feet of LMR240 coax running to the basement. I
measure SWR at the following frequencies on simplex.

144.2 2.5
145.2 2.4
146.2 2.3
147.2 1.9
147.9 1.7

Can I conclude that the antenna is electrically short for the 2 meter
band?



Have you a common mode choke on the feedline? J-poles are nortorious
for feedline common mode problems.

Danny, K6MHE


Maybe a 4-5 loop coil of coax close to the feed point?

Thanks, jimbo