[TowerTalk] Rotor Cabling Query

[Joe Subich, W4TV]

> A primary point/concern of my post is the length of the run on the 
> temporary 300 ft and to the final goal of 700 ft. What size of the 
> conductors/wire/cable to utilize for the effort. Some part being
> heavy duty 8 conductor rotor cabling in conjuction with splices
> and/or runs of UF solid wire cabling from 14 gauge to 10 gauge such
> as 14/3, etc. or other such ideas on conductor size.
You will need to figure out those trade-offs for yourself in your
particular installation.

The brake solenoid in the Ham IV/T2X is rated 24 VAC @ 5A.  The brake
uses wires 1 and 2 (the "heavy" wires).

The motor in the Ham IV/T2X is rated 20 VA @ 2.25 A.  The motor uses
wires 4, 5, 6, and 8 plus wire 1.  Rotation power is supplied to either
5 (rotate right) or 6 (rotate left).  4 and 8 are the capacitor
connection and the return in wire 1.

To energize the brake you have the voltage drop of (0.75 Ohm + the
resistance of wires 1 and 8) x 5 A.  To turn the motor you need to
overcome the voltage drop of (5.0 Ohms + wire 5 or 6 + wire 4 +
wire 8 plus wire 1) x 2.25 A.

I do not know how much voltage sag the brake or motor can handle before
they stop working reliably but I would not allow more than 2V drop as
a first estimate.

The typical "light duty" eight wire rotator cable is 2 x #18, 6 x #22.
DX Engineering says "suitable for most controller to rotator cable
runs of less than 125 feet."  You could probably back out the voltage
drops for a 100' run and use that as a "safe" limit.   The so called
"heavy duty" rotator cable is 2 x 16, 6 x 18 but is probably marginal
at 300 feet.


73,

    ... Joe, W4TV


On 2021-04-02 7:10 PM, CEPitts wrote:
> I would like to hear from those in regards to ideas for the following. I 
> know there are those who have long runs of control cabling for rotation, 
> switching, etc. so I seek your ideas and advice.
> 
> I have a need for a temporary set up of a run that is 300 feet from the 
> operating position shack/controller to the top of the tower controlling 
> a Ham 4 rotator. The final set up with be a run of 700 feet from tower 
> to the operating position shack/controller
> 
> Would it be best to provide a disconnect near the connection point at 
> the top of the tower with a short pigtail to the Ham 4, as well as a 
> disconnect/splice point at the bottom of the tower, and a final run to 
> the shack/controller?
> 
> Based on previous discussions/ideas tossed around here within the last 
> 2-3 weeks I would most likely take some ideas from the group in regards 
> to utlizing trailer type connects/disconnects and also splices within 
> the entire run.
> 
> A primary point/concern of my post is the length of the run on the 
> temporary 300 ft and to the final goal of 700 ft. What size of the 
> conductors/wire/cable to utilize for the effort. Some part being heavy 
> duty 8 conductor rotor cabling in conjuction with splices and/or runs of 
> UF solid wire cabling from 14 gauge to 10 gauge such as 14/3, etc. or 
> other such ideas on conductor size. A reasonable cost/maintenance 
> perspective would be ideal keeping in mind going from the 300 ft to the 
> 700 ft in the future and ease of said transistion. None of this will be 
> buried, I have that part taken care of.
> 
> *(tower/rotor)*****short pigtail/run-->>>---*****(pigtail/connect 
> splice)*****run to bottom of tower -->>>-->>>-----*** **(bottom of 
> tower/connect splice) *****--->>>---->>>---*-****temp 
> run*****>>---->>>>>>>---->>>>>>----->>>>>>>------>>>>>------->>>>> 300 
> ft expanding to 700 ft>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> (later 
> to be the permanent run)>>>>>>>>>>>>>>*** **to connect/splice back to 8 
> conductor rotor cable ham 4 controller in shack.****
> 
> Besides possibly utilizing trailer type connects/disconnects I was also 
> considering utilizing 8-10 conductor terminal blocks for 
> splices/junctions etc. and I could possibly place those in weather 
> resistant boxes at those points where required....What is the thought on 
> that approach?**
> 
> Thank you for all the input/ideas and73! Ed K5OF in NC
> 
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