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Re: [TowerTalk] Evaluating a Mosley TA-33 for purchase

To: "Derek Cohn/WB0TUA" <>,"Towertalk" <>
Subject: Re: [TowerTalk] Evaluating a Mosley TA-33 for purchase
From: "Paul Christensen" <>
Date: Tue, 23 Jan 2007 20:44:15 -0500
List-post: <>
> My understanding is that the traps on older Mosley beams can be 
> troublesome.

Prior to the purchase, I would assemble the driven element and elevate it at 
least 16' above ground.  Connect suitable cabling and check VSWR on 20/15/10 
meters.  This will provide a clue if the traps have been burned.  The 
reflector and director traps will not be subject to the same extreme heating 
that can occur as on the TA-33 driven element.  This was a significant 
problem for ops such as myself who purchased a TA-33 Jr. as a novice, then 
upgraded our licenses to run the full legal limit.  Mosley offered the MP-33 
driven element in response to the many burned out TA-33 Jr driven-element 

Finally, I would check the integrity of the four phenolic driven-element 
stand-off insulators to ensure they are not cracked from UV and/or 
over-stress.  Mosley used to provide a liquid UV protectant that was applied 
with a brush from a half-pint-sized can.  It actually did a good job of 
protecting the antenna and went on like a varnish.

Other items to check are corrosive and stripped hardware as well as possible 
cracks on the black plastic used on the trap ends.  Any hardware requiring 
attention should be replaced with stainless steel at every opportunity.

Paul, W9AC


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