Yes, but lightning is not DC. It is a series of short duration pulses
resembling AC and should be treated accordingly with little to no inductance
in the path. Thus any inductance in line would actually prevent the energy
from going to ground.
For lightning protection on balanced feed systems, see The Wireman model
#878 as one good example. Just about every series fed broadcast tower uses
an "arc gap" method for that purpose. I find that a pair of small engine
non resistive sparkplugs mounted on suitable hardware which is adequately
grounded does an excellent job and with no issues at legal PEP power.
The old knife switch approach is OK........... if one remembers to put the
switch in the proper position when lightning is around or the station goes
QRT.
73
Bob, K4TAX
----- Original Message -----
From: "Robert Arenella" <rja12@comcast.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Tuesday, July 30, 2013 8:01 AM
Subject: Re: [TenTec] OT: Openwire/Window Line and Bad Wx
On 7/29/2013 11:31 PM, Richards wrote:
> A second question is what lightning protection devices are preferred
> for securing open transmission line?
>
> =============== K8JHR ================
I'm not sure what is "preferred", but what I use is a large DPDT knife
switch, one side to the tuner, the other position to ground.
Although I don't use one, there is always the ever-popular dual spark
gap as shown in the old (and maybe newer?) Handbooks.
Finally, for static mitigation there is the high value resistor from
each open wire conductor to ground.
73,
Carter K8VT
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Another option is to use a pair of plate chokes from each half of the
feedline to ground. I have a friend up in NH using this setup. Keeps the
antenna & feedline DC grounded. Lightning isn't his big problem, static
electricity generated by blowing snow was creating havoc at his station.
The chokes solved the problem.
73 de bob,
N2OAM
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