I'll look into Wireman!
Larry Wo0Z
On Thu, Jul 26, 2012 at 5:44 PM, Steve Jones <n6sj@earthlink.net> wrote:
> Larry-
>
> If you go directly to the M2 website, open the .pdf file for the OR2800
> rotator. On page 8 of 11, there is a table titled "Cable Information". They
> tell you how big a wire you need for various distances. You'll need 14 AWG
> for the motor power wires for 250'. Wireman makes a custom cable for the
> Orion which M2 recommends.
>
> 73,
>
> Steve
> N6SJ
>
> ----- Original Message ----- From: "Larry Loen" <lwloen@gmail.com>
> To: "TowerTalk" <towertalk@contesting.com>
> Sent: Thursday, July 26, 2012 2:44 PM
>
> Subject: [TowerTalk] Resistance of Rotor Control Wires (see also CAT5
> thread)
>
>
>> I am trying to understand control wire (DC) resistance losses. This
>> would be for my rotor control wire for my M2 atop my
>> soon-to-be-erected 72 foot tower.
>>
>> I figure my total run is going to be fairly long -- about 215 feet
>> (for a variety of reasons, a straight cable run is not in the cards --
>> I have to go around my septic field and a shed). The specs for the M2
>> rotor http://www.arraysolutions.com/Products/m2rotators.htm . . .show
>> the minimum cable gauges are 2 at number 18 and 2 at number 22. This
>> probably relates to the total amperage delivered and the planned
>> voltage drop the unit can stand.
>>
>> Calculations given here:
>> http://www.stealth316.com/2-wire-resistance.htm . . .are suggestive
>> that I would want more like number 12 gauge if I wanted to keep the
>> voltage loss to half a volt (apparently, the M2 design can stand a bit
>> more?). There are a couple of other sources, including this one:
>> http://www.mogami.com/e/cad/wire-gauge.html which, while it
>> dispenses with the "circular mills" part of the calculations (at least
>> overtly) seems to me to create a similar conclusion.
>>
>> This suggests to me that I should be looking at some hefty cable
>> gauges if I want to be "really sure" of things working, but I get the
>> impression that this is probably overkill, given what M2 itself seems
>> to be recommending. A 72 foot tower would have a minimum run (if one
>> wanted to keep the shack out of the fall zone) of about 150 feet for a
>> 75 foot total tower exposure. And, I know M2s are popular with
>> VHF/UHF hams, where a lot of towers are taller still. I'm sure lots
>> of M2s have 200 plus foot runs.
>>
>> Still, in line with my overengineering of the project, what I probably
>> would find ideal is some sort of four wire shielded cable at somewhere
>> between 12 and 16 gauge if I could find such a thing. Or, would
>> unshielded with a couple of ferrite beads at nor near the rotor be
>> enough? That would simplify things quiet a bit.
>>
>> CAT cable looks suspiciously narrow gauge for my run, at least.
>>
>>
>> Larry Wo0Z
>> _______________________________________________
>>
>>
>>
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>>
>
>
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