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[TowerTalk] Cushcraft 40 meter Beam ???

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Subject: [TowerTalk] Cushcraft 40 meter Beam ???
From: (Gary R. Hosler)
Date: Wed, 12 Nov 1997 14:01:00 -0600
Not sure how the toroids will help with this problem Steve.  I can see that
they might help break up any RF on the outside braid but the other half of
the antenna driven element is connected (via the coax) to the analyzer.
Wouldn't the near field strength from the BC station be picked up by the
antenna and carried via the center conductor to the analyzer where it would
be rectified by the diodes in the front end?  For instance, when the
analyzer is connected to a 160M vertical, the braid of the coax is at
ground potential (ground rods, counterpoise, etc.).  It is the RF pickup at
the antenna (which is connected to the center conductor of the coax) that
is rectified in the analyzer that produces the problem.  Perhaps I just
missing something in the explaination.  Sure hope so as your toroid stack
would have helped me a number of times when the field strength from a local
BC station overwhelmed the analyzer (I have both the MFJ-259 and the Autek
RF-1).  Could you shed some light on this?  Thanks in advance for your

de Gary  W0AW on 11/12/97 11:39:56 AM

cc:    (bcc: Gary R. Hosler/MIPP/Imation)
Subject:  Re: [TowerTalk] Cushcraft 40 meter Beam ???

In a message dated 97-11-12 10:48:15 EST, writes:
> You may be getting interference from nearby broadcast stations. The MFJ
>  runs just microwatts, so it wouldn't take much to upset the readings,
>  especially at that height. I live withing 4 miles of a 50 kw AM station
>  can see the effects with a tribander at 40 feet.
    And the AEA analyzer as well. I've got a coax jumper with stacked
on it to use in cases where I've probably got some nearby RF problems.
     I've got the MFJ 259 and I use it ALL the time.
73,  Steve  K7LXC
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