----- Original Message -----
From: "Marco Spalluzzi" <marco.spalluzzi@orobiacom.it>
To: <cq-contest@contesting.com>
Sent: Friday, June 03, 2005 1:42 PM
Subject: [CQ-Contest] Slopers and rotators
> Hi guys, I have to report a strange experience happened to me.
> I had a fault inside my g800dxa rotator this january, while running
> the ARRL
> rtty roundup.
> I replaced the potentiometer inside the rotator at half march, than
> I had
> the same fault at the beginning of may, while working in the ARI
> contest.
> In both cases, I spent a few hours on 40 and 80 working with 2
> slopers,
> during the night.
> In slopers, as you know, central wire of coax is connected to the
> sloping
> wire, shield is going to tower/mast/whatever is grounded.
> Using slopers, tower/mast is to be considered as a radiating part of
> the
> system (the missing half of the dipole), so there's a current
> flowing in the
> mast.
> Could this be the reason of the potentiometer fault?????
> It sounds strange to me, cause I'm not the only one in the world
> using
> slopers, but after what happened I'm not too sure...
> What do you think?????
I once tried shunt-feeding my tower and immediately burned up the pot
in a T2X rotator, so it can definitely be a problem.
Standard advice is to route all cables inside the tower, and bring
them all the way down to ground level. Perhaps ferrites and bypass
caps at the rotator end would help.
Dave Hachadorian, K6LL
Yuma, AZ
.
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