I found I had some intermittent changes in SWR on 160M (shunt feeding the
tower). I put a grounding strap from the mast to the top of the tower
(across the TB-3). SWR has been stable since. Have not bothered to put a
ground strap across the Prosistel.
Have a MonstIR. Was going to short out the passive elements to the boom. But
I am getting the 60/80M add-on kit so won't be able to do that except for
the 1st Director. Will ground that and see what it does for top loading on
160M. Even without grounding the elements I can move the SWR on 160 all over
the place with running the elements in and out on the MonstIR. There seems
to be no arcing or sputtering so far on topband.
N2TK, Tony
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of jim Jarvis
Sent: Wednesday, July 30, 2008 4:06 AM
To: towertalk@contesting.com
Subject: [TowerTalk] Grounding mast?
Been following the SteppIR v. Stepper.IT thread while travelling.
Had a few minutes to browse both websites, this morning,
and came across a short commentary about lightning and ESD protection
for the steppIR.
It raises the question of static charge buildup due to wind motion,
in (one assumes)
drier climates. Points out lack of conductivity across rotors, and
asserts 300-500V per meter
above ground as the possible potential buildup. Routed into the
shack, if the charge isn't
bled off.
The discussion recommends a positive ground between the mast, and the
tower, as well
as a good dissipative ground for the tower itself, as lightning
protection would dictate.
The physics of this are real. What amazes me is that this is the
first time I'm seeing the
discussion, in these terms. Does anyone actively ground their mast,
across the rotor?
Firsthand experience?
n2ea
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