Roger,
Your humor is amazingly dry!
73,
Gordon Beattie, W2TTT
201.314.6964
w2ttt@att.net
w2ttt@arrl.net
w2ttt@att.com
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of K8RI on TowerTalk
Sent: Wednesday, 09 August, 2006 01:46
To: TowerTalk
Subject: Re: [TowerTalk] Testing ICE arrestors
Test Metal Oxide Varistors (MOVs) at their working potential. Every over
voltage, even testing, degrades them.
I would caution uses of Polyphasers not to use this method of testing.
Normal MOV failure mode is shorted. If they have failed open it is usually
quite evident.
MOVs failing open are usually nothing but a pair of leads pointing to where
the MOV had been located.
You should try standing next to a 50,000 Joule MOV when it lets go. <:-))
Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com (Use return address from home page)
The surge suppressor for ICE rotator controls uses MOVs in parallel with
capacitors for each lead. Typical failure modes of each is a short
circuit or low resistance. I wouldn't hi-pot them, either. Energy from
the hi-pot may cause an MOV to fail if it is applied for too long a time.
73 de WOØW
Jim McDonald wrote:
>How can one tell if used ICE coax arrestors or 8-conductor control cable
>arrestors are still good? DC continuity on the center conductor of the
>coax
>arrestors? DC continuity of the control cable arrestors? SWR connected to
>a dummy load for the coax arrestors?
>
>Jim N7US
>
>
>
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