[TowerTalk] RMC 1000 Remote cable

Jim Lux jimlux at earthlink.net
Thu Nov 3 15:02:49 EST 2005

At 11:13 AM 11/3/2005, Rick Karlquist wrote:
>Barry Merrill wrote:
> > If you havent bought the Remote control, unit, yet, don't.
> >
> > I recommend that you will never want to be away from the
> > base of the tower when it goes up or down, so you can
> > stop it when something goes wrong.  And especially with
> > the cable arms you get from US Tower, which are way too
> > short.  I've had numerous wind gusts push the cable
>I bought my tower from W6BH.  They replaced all the crankups
>at the Table Mountain remote site for this reason.  They
>needed to be cranked down in case of a wind storm, but it
>was not possible to drive an hour and a half up to the mountain
>to baby sit the tower.  They said they had a disaster on the
>10 meter tower like you describe.  I noticed that one of the
>coax arms I got was bent, like it had been in an "accident".
> >
> > And, what really frosted me for the $1000 option was
> > the realization there was no feedback of the elevation
> > of the tower, other than UP or DOWN.  I had originally
> > thought I could use the remote to experiment with
>UST built some of the HDX5130 towers with an elevation indicator.
>Not sure how it worked.  Maybe they would sell you a retrofit
>kit for a handsome price.
>The control box is rather trivial, and you could easily build your
>own.  But you don't want to use their design because it puts 120VAC
>on your control cable, unnecessarily.  Someone posted on TT and
>improved scheme with only low voltages, using some auxiliary relays
>at the tower.
>On and off, I have tried to brainstorm some sort of giant reel that
>would wind up the coax as the tower cranks down and pay it out as it
>goes up, all the time being under controlled tension.  I haven't hit
>upon a scheme I really like.  You either need a rotary joint

A rotary joint shouldn't be a big deal for HF.  We use a variety of N 
connector rotary joints on the antenna range at JPL, and they are fairly 
wide band.  I would imagine you could find one surplus.

Even if one had to make such a thing, I think you could modify something 
like a DIN 7/16 or a N connector.

The constant tension reel is a fairly common device.  They use a spring 
steel tape as the tension member (think in terms of a tape measure).

There's also a very handy device called a "string pot", which is used to 
measure linear motion.  As one might imagine, it's basically a multi turn 
pot (either geared or not) with a constant tension type reel and a steel or 
spectra cable on the drum.

>the coax has to double back on itself etc.

That's the other approach.. put the spring loaded reel in the middle of the 
span and pay out two cables.  Again, this is an off the shelf item, 
although I've only seen it for things like clothesline.

>   No obvious simple way
>to do this or somebody would have done it already.
>Rick N6RK
>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless 
>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with 
>any questions and ask for Sherman, W2FLA.
>TowerTalk mailing list
>TowerTalk at contesting.com

More information about the TowerTalk mailing list