Tony,
Here's my advise for you. Note, worth reading for others too:
Bill, N3RR
>Adding a bunch of ground rods and attaching #4 solid
> wire with Cadweld one-shots to my tower.
>
Ok so far.
> I am moving the receive coax switch from the tower to my shed - much
closer
> to the receive ewes/pennants. My coax/control wire bundle from the house
> passes the shed on the way to the tower. The shed is 30' from the house
and
> the tower is 100' from the shed.
>
> - Should I put a ground rod(s) at the shed where the receive coax switch
> will be mounted?
Yes, and consider this:
Where ever you have such a situation (coax switch, or common node point
where coaxes converge),
you should have a ground, preferrably a single point ground (SPG). So, I'd
add a SPG at the shed where the coaxes from the tower 70 feet away meet with
the
coaxes form the EWEs/Pennants and travel to the house from there.
> - Should I run something like a #6 or #8 ground wire from the tower to the
> receive coax switch? If so, should it be separated form the coax/control
> cable bundle?
It won't hurt to run #6 between the tower and the shed. Be sure to put
ground rods
every N feet along that 70 foot run. (N= 2 times the length of the ground
rods).
Also, I'd run a #6 wire from your shed to your house, again with ground rods
every N feet, and tie
that ground wire into your SPG ground at your house. (Again, use proper
procedures here.)
> - Is it a bad idea moving the receive coax switch to a separate location
> from the tower, or doesn't it matter?
It doesn't really matter as long as all the other proper procedures are in
place,
such as: coax grounded at the top and bottom of the tower, tower grounded at
all three legs,
SPG panel grounded at shed using proper procedures.
>
> As a side note, here are some things that I have happened recently.
> Started adding more ground rods as I only had 9 that were cadwelded with
#4
> stranded copper wire. Rods have been in the ground 8 years. With an easy
> yank two of the stranded wires came off the ground rods. The ends of the
> wires were not shiny. Don't know if they corroded or if they were weakened
> by the cadweld.
> Presently replacing all of the stranded wire with #4 solid wire besides
> adding 9 more rods.
All wires should be solid not stranded. Good thinking.
>
> Also, noticed that the antennas- 40, 80 and 160M, which go through a coax
> switch 4' above ground on the tower, had their resonant points go a little
> lower in freq, plus were now broader. Turned out to be the shield of the
> 1/2" hardline is open. Got it isolated to 15' which is buried under a
flower
> bed. There are no splices in the hardline. I guess the shields of the
other
> hardline were acting as the return path? The other 3 hardlines have their
> shield grounded to the bottom of the tower. The hardline that went to the
> coax switch was not grounded at the bottom. Was counting on the ground
strap
> 4' up at the coax switch.
Not proper procedure. All coaxes must be grounded individually. Also, do
not
rely on the coax connector for the ground connection of the shield. Use a
ground kit.
Reason - the coax connector is either soldered or not, either way, the
connector
is the weakest link when lightning strikes. This is one of the most
commonly
overlooked grounding procedures (mistakes).
>Guess I better ground that shield at the bottom
*Yes*
> too. Not sure if the difference in height of the grounding kits or the
lack
> of enough tower grounding caused this problem.
It's probably both. Grounding of the coax should take place at the lowest
point possible on the tower.
Reason - the lower you ground the coax, the lower the Voltage potential,
thus minimizing the chance that the
potential (Voltage) during a strike will increase as the coax run proceeds.
>
> 73,
> Tony
> N2TK
>
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