I recently posted a question regarding tuning a triband beam prior to
mounting it on the tower. I built it on a mast about four feet above the
ground. I wanted to know if I should try tuning it at four feet before
mounting it. The antenna is a Cushcraft A4S with the 40m add on kit. Thanks
to all that replied. Answers fell into three categories: 1-tune it on the
mast at four feet where I could easily reach it, 2- turn it facing straight
up with director just off the ground and tune it, and 3- just build it to
Cushcraft specs and mount it on the tower without tuning. I tried number 1,
and got OK readings on 10 and 15; 20 and 40 were way low (out of band). I
tried adjusting the antenna without much change. I didn't try number two, as
I couldn't turn it up alone. I reset it to the specs in the manual and today
we put it on the tower at 75'.
To my pleasant amazement, the 2:1 SWR points were 10m 28.0 to 29.4, 15m 21.0
to 21.450, 20m 14.0 to 14.350 and 40m 7.080 to 7.220. Guess the number three
guys were right!
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