TT:
Speaking of lightning and Polyphasers, I've often wondered about the
use of PL259's with lightning suppressors/arrestors. I've seen it written
on this reflector numerous times that one should not rely on a soldered
connection to a ground rod or other grounding conductor. During a
high-current strike this connection would melt and the electrical path to
ground would be destroyed. I agree with this recommendation because it
makes sense.
Yet on these very same pages many of us expound upon the wisdom of
using lightning suppressors with (soldered) PL-259 coax connectors. Should
there not also be a mechanical connection from the coax shield to a nearby
ground point just ahead of the Polyphaser or other suppressor? (The
installation at my tower has this configuration by virtue of the shield
ground at the base of the tower, a foot away from the suppressor on each
coax run. But it was coincidental that the shield is grounded so close to
the lightning suppressors at this QTH.)
But what of the soldered center conductor? Wouldn't this connection
also melt during a high-current strike?
My professional experience with such suppressors has been at commercial
tower installations where hardline coax and mechanical compression
connections to the shield and center pin are the norm. But the use of
soldered connections in amateur lightning supression is troubling - at least
to me. I hope the QST articles shed some light on this question.
73 de
Gene Smar AD3F
-----Original Message-----
From: Pete Smith <n4zr@contesting.com>
To: towertalk@contesting.com <towertalk@contesting.com>
To: <towertalk@contesting.com>
Date: Tuesday, May 14, 2002 4:17 AM
Subject: Re: [Towertalk] Lightning Protection by Ron Block in QST!
>At 06:31 PM 5/13/02 -0500, WA9ALS - John wrote:
>>It's great to see this subject get some attention in QST! -Maybe- it will
>>help dispell some of the myths about lightning protection.
>
>I agree, as long as the Polyphaser guys acknowledge that most ham
>installations do not need to be connected to their antennas 24/7, and that
>their solution will not be cost-effective or EFFECTIVE, period, for many of
>us. Unless you know you have an adequately low-inductance ground
>connection for your station, all the line protectors in the world will not
>protect your equipment against a lightning hit. I'd much rather disconnect
>every conductor outside the house and know I'm safe than gamble on being
>able to hold my shack at ground potential through "the big one."
>
>73, Pete N4ZR
>
>_______________________________________________
>Towertalk mailing list
>Towertalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
|