The SWR should not change much if you check it at 30-40 feet high. I would
think the full band setting would be the most common so I doubt that you are
the first one to have a problem. Is this an OWA antenna? OWA designs usually
cover the whole band plus.
Subject: [TowerTalk] M2 20M5 Yagi
Date: Thu, 16 Feb 2012 19:23:59 -0500 (EST)
Interesting story about this beam.
I posted a few weeks ago about the M2 20 meter Yagi and was looking for
anyone with experience with the beam.
After hauling the beam up and down the side of a test tower I felt
something wasn't right with the antenna. Usually a 20 meter antenna up around
feet or so will have its SWR dip lower in frequency than when it is mounted
at its final height. This one dipped higher in the band, around 14250. I
finally called M2 and to my surprise Mike told me that for almost 10 years
the dimensions in the instruction manual have been wrong...only for the
full band setting. Apparently, no one had ever had this problem or had ever
notified them about it.
For those of you who have this beam and want to use the "full band"
setting, add four inches to the driven element on both sides. I did it and
SWR is where it should be at a low height. The dimension change instruction
is from Mike. You may not have enough length on that 1/2 inch tubing to
Mike was quick to get back to me and was kind enough to send the new 1/2
inch tips second day air..in time for the big tower/antenna party next week.
Hats off to M2 for great service.
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