[TowerTalk] 2 questions

Joe Subich, W4TV lists at subich.com
Sat Jul 7 20:00:15 PDT 2012


 > First question. I have an Ameritron RCS-10 that doesn't seem to work
 > on all positions. Mine only works on 1-4 with no connection on the
 > other positions. What would cause that? It almost seems like 2 and 6
 > are hooked together and 1 and 5 too!

RCS-10 uses a "binary tree" arrangement of relays.  You will probably
find the input relay has been arced so that both the normally open and
the normally closed contacts are connected at the same time (all the
time).

 > Second question is about the need/benefit of grounding coax cables at
 > the bottom of a tower.

It's called lightning protection.  You want the shield of all cables
connected at both the top and bottom of the towers so that a lightning
strike can't cause a high voltage between the tower and cable shield
which would "puncture" the insulation and put the high voltage on the
chassis of any connected equipment.  There is a lot more in the literature.

73,

    ... Joe, W4TV



On 7/7/2012 8:05 PM, Gregg Seidl wrote:
> First question. I have an Ameritron RCS-10 that doesn't seem to work
> on all positions. Mine only works on 1-4 with no connection on the
> other positions. What would cause that? It almost seems like 2 and 6
> are hooked together and 1 and 5 too! I also noticed it seems it has a
> lot of "bleed thru" for the lack of a better term. I have thinking
> about getting a new switch but what would I get that would be any
> better? Does someone make a switch that would follow my Icom IC-7800
> and PW-1 band wise? How do they plug-in? I know I'm getting lazy but
> what is wrong with that,why not make it easier?
>
> Second question is about the need/benefit of grounding coax cables at
> the bottom of a tower. I am recabling my antennas after years of
> using the same cables. I have read where you should ground the sheild
> toward the bottom of the tower so I bought those grounding clamps
> from DX Engineering and they same really nice but why do you need to
> do that? The tower in question is 85 feet tall Rohn 45 and has a 40
> meter CC beam on it and also a CC WARC rottable dipole  plus a 75
> meter interted V on a metal sidearm. None of those antennas are at
> ground potential. It seems to me that there is just more connectors
> to go bad at some point. The tower is well grounded with 3 25 foot
> legs of number 0 copper wire with ground rods every 8 feet along the
> 25 feet of wire. It works too as the tower has been drilled by
> lightning at least once with no damage, cables were disconnected from
> gear and tied to my station ground. Just trying to understand and
> learn why some say to tie the sheilds to ground at the tower base.
>
> Thanks
>
> Gregg K9KL _______________________________________________
>
>
>
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