Some years ago, I bought a 5 element M2 6M yaghi. I had the same problem that
you are having. What I did was really stupid and it is taking a lot of courage
to publicly admit my mistake: I assembled the antenna backwards. That is, I had
the last director in the reflector hole and the reflector in the last director
hole. I stood there and looked at the antenna. It looked kind of funny. I got
out the tape measure. When I put the elements in the right holes in the boom,
the SWR went right down. Do not want to insult you, but take a look before you
start replacing the matching section, etc.
Buddy Morgan WB4OMG
On Mar 5, 2012, at 3:50:14 PM, ejh <wm3m@live.com> wrote:
From: ejh <wm3m@live.com>
Subject: [VHFcontesting] Need help with Cushcraft A50-3S - high SWR
Date: March 5, 2012 3:50:14 PM EST
To: vhfcontesting@contesting.com
I have a new Cushcraft A50-3S, 6 mtr beam, and I am having trouble getting the
SWRs down.
I measured multiple times the element lengths and set them to the 50 Mhz sizes.
I then set the gamma match to the exact sizes shown in the manual, (set and X)
but even installed on my roof away from all objects the SWR was very high, way
too high for my transceivers. I kept adjusting the gamma match and the only way
I could get SWRs down low enough to work with my rigs was to make it as short
as possible with the small rod pushed all the way inside the larger rod. But
even then the SWRs were well above 2 at 50.125 mhz? I have worked with it for
many hours and I am unable to figure out how to adjust the gamma match
correctly.
This is replacement for a damaged A50-3 I had for years, did not have problems
with the old one. The gamma match on the new one is different, on the new gamma
match the small rod does not make contact with the larger tube it slides into.
I tried two different, new lmr-400 coax runs, no change.
I sent email to Cushcraft/MFJ but they have not answers previous emails, so
don?t suspect I will hear from them. Any help would be appreciated. Thanks
Emory
WM3M
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