Open your wallet!
> Date: Fri, 27 Jul 2012 11:05:34 -0700
> From: lwloen@gmail.com
> To: n6sj@earthlink.net
> CC: towertalk@contesting.com
> Subject: Re: [TowerTalk] Resistance of Rotor Control Wires (see also CAT5
> thread)
>
> 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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> >> TowerTalk@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/towertalk
> >>
> >
> >
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