I have questions about the best way to get cables (coax, AC, and
control) from the shack to the tower.
Here are the things I have read or observed and am trying to take into
account. Please correct me if I am wrong on any point.
1. Low-voltage wiring (e.g., for rotor and other control functions)
cannot be run in the same conduit as regular power wiring.
** True, I run mine in a separate conduit underground, just makes good sense
to me.
2. All cables should run in grounded metal conduit for effective
lightning protection, according to Polyphaser.
** I do not do this, I can not see what difference it would make really, if
I remember, above ground has to be metal and underground can be schedule 40
3. The bends in the conduit for a single run of cable may not exceed 360
degrees or it becomes too difficult to pull the wires through.
** I would agree, why would you want to anyway?
4. EMT is not buriable. This suggests that RMC must be used, but can it
be bent? Or can liquid-tight flexible metallic conduit be buried, and
does it provide sufficient protection? Is there a means of grounding the
metal in such conduit?
** I hate pulling cable through flexible metallic conduit, I avoid it at all
costs:)
It looks as though I will need three separate runs of conduit: one for
the feedlines, one for power for the crank-up, one for the control
cables and rotator power.
** I run two with no problems, one for AC power and one for coax, control
cable for Steppir and rotator, I have no coupling. I would add that modern
Yaesu rotators use DC and so does the steppir, so I do not see a problem.
The conduit run for 120V power looks like needing six 90-degree bends
(two too many), and the other cables eight (double the permitted number).
** Don't know about the code on this, but using 90 degree sweep bends makes
it easier and I think the electrical code requires this anyway, the less the
bends the easier to pull cable, anything more than three and it gets very
difficult. I would put a ton of talcum powder in the conduit to help.
Mike
How have others handled their cabling?
73
Alan NV8A
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