TT:
I read, possibly here back in the late 90s, a recommendation to
wind a few turns into the rotator control cable at the tower top and
bottom to create some impedance against lightning surges. I did that,
using short pieces of 2" PVC tubing and tie wraps to fasten the turns.
I also ran the control cables, along with the coax, inside my Trylon
tower's angluar leg members. Finally, I installed a set of Polyphaser
MOVs at the SPG outside the shack. That is, the surge arrestor for the
control cable runs down the tower and through the steel box at the
bottom, into the conduit system and up to the SPG where it hits the MOVs.
I realize that a direct strike onto the tower will probably blow
right through the control cable whether there are a few turns in it or
not, but it was cheap.
73 de
Gene Smar AD3F
On 10/15/2021 11:05 AM, john@kk9a.com wrote:
Rotator cables typically have no shield to bond to the tower. I use MOVs
near all of my rotators to protect the motors and potentiometers.
John KK9A
Michael Tope W4EF wrote:
Jim, et al:
What about control cables coming down the tower? I just skimmed through
the first edition of Ward's grounding book. It recommends bonding the
coax shields to the tower, but doesn't say anything about control
cables. Typically there is a least one rotator control cable in the mix
and oftentimes additional control cables for array switches and multiple
Tic ring rotators on larger more sophisticated installations. That seems
like an inconsistency, no?
73, Mike W4EF...........
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