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[TowerTalk] Cushcraft 40 meter Beam ???

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Subject: [TowerTalk] Cushcraft 40 meter Beam ???
From: (Roderick M. Fitz-Randolph)
Date: Wed, 12 Nov 1997 13:57:39 -0600
>I have a forty meter two element cushcraft beam on 160 foot Rohn 45
>tower, newly mounted. It checked using an MFJ 259 at 1.1 to 1 at
>7.100 mhz on the ground at ten feet on a test tower. Now after raising
>to 160 feet it checks 2.5 to 1 at 7.200 mhz, with no real match
>anywhere near forty meters. Now it has been taken down and checked
>from elbow to you know where and it is still at the correct settings for
>the book and checked good on the same MFJ meter. Then it went
>backup to 160 feet and you guessed it it now is at 2.5 to 1 and doesn't
>show a big dip on the meter.
>Question the antenna is notgrounded well to the tower yet it is
>suspended by the bearing plate and clamps above the bearing, could it
>not being grounded to the tower be causing the interaction or what?
>Any Ideas please post here, as we have several friends trying to sort
>this out. Ideas or suggestions are appreaciated.
>Thanks and 73
>Ken ( gettin tried of climbing)
Ken, several items spring to mind.

(1) Check that coax out thoroughly!

(2) Don't trust the MFJ-259 if you are in the vicinity of a broadcast
    station. (I can't get a reading on my 40, 80, or 160 at height with
    the MFJ-259 because of the very strong field of rf put out by a
    nearby (half mile) broadcast station.

(3) You didn't state whether it was checked at height with the MFJ-259
    or with your rig's SWR meter.  I'd rely on the rig's SWR meter rather
    than the MFJ.

Hope you find the problem

Rod, N5HV

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