Those aren't that heavy an antenna...
I'd look into one of the leadscrew positioners used on C-band satellite
dishes. They're readily available surplus, and have suitable thrust and
speed(not too fast). I've seen both AC and DC powered ones. Limit switches
are nice..
Places like McMaster-Carr have bare ACME thread leadscrews and follower
nuts, if you've got a motor to drive them. Put the follower in the end of a
piece of pipe, and spin the screw.
A garage door opener is also probably in the right ballpark motor size and
speed wise (and, has limit switches, and even a remote control!).
You could also try to cobble up something with cables and motorized winches
(if you have a source for an inexpensive reversible winch, this might not be
a bad idea)
If you want to just buy a surplus lead screw positioner: C&H Sales in
Pasadena CA has the following (don't know if it's suitable, or reasonably
priced, but this is the idea.. The description doesn't say what the travel
is, but you could probably call them. It's probably a couple feet.)
LINEAR ACTUATOR #820154. Motor is rated 24 VDC. The motor running without a
load on the actuator shaft pulls 1.0 amp. The unit has built-in Micro®
switches with a gearbox driven cam system. The switches and cams are set to
stop the actuator travel at the extremes of its travel. This limit switch
sys tem can be set to limit the actuator travel anywhere within the actuator
travel range. Additionally, a 27-slot encoder wheel and pulse producing
slotted pick-up system are built into the main gearbox. This encoder wheel
rotates at the same speed as the actuator screw shaft. This system allows
close positioning of the actu ator shaft. The encoder pick-up unit requires
12 VDC for operation. The unit runs until the limit stops are reached in
either direction. The unit stops automatical ly when it reaches either limit
stop. The unit can then be reversed by reversing the polarity of the input
volt age. The actuator motor is a permanent magnet DC type and will run on
lower voltage if desired. The motor/gearbox/encoder/limit switch assembly is
mod ular in design and lifts out as a unit for service or adjustment. The
internal parts are enclosed in a sturdy cast aluminum enclosure. The
enclosure has a sturdy lid and sealing gasket. Ideal for outside uses such
as steering satellite dishes. As supplied the actuator has a 6 ft. long
multi-conductor PVC insulated cord for elec trical connections. The actuator
rod end has a swivel ing ball and socket end fitting. The bore of the ball
socket is 1/2". The width across the face of the ball socket is 5/8" Overall
dimensions: 8-3/4" wide x 5" deep x 36-1/2" long (with actuator rod
retracted). Stock #DCLA9801
----- Original Message -----
From: "Richard Thorne" <rmthorne@cox.net>
To: "Tower Talk (mail list)" <towertalk@contesting.com>
Sent: Saturday, January 29, 2005 7:55 AM
Subject: [TowerTalk] Vertical Automatic Tilt Over
> I live in a restricted neighborhood but I would like to put up a
> Cushcraft R8 or Hygain 640 10 through 40m vertical.
>
> I plan on installing it on a tilt over mast so it will be out of site
> when not in use, I think the neighbors could live with that.
>
> So I got to thinking it would be nice if I could hit a switch in the
> shack to tilt it over or tilt it up.
> I was thinking I could sandwich a 2" alumium mast between a pair of
> 4x4's with a bolt at the top for the hinge point.
>
> Has anyone seen such a device. I'm sure this will have to be home
> brewed using an air cylinder or maybe a rotor and some limit switches.
>
> Any ideas?
>
>
> Rich Thorne
> ARS: N5ZC
> AMA: N5ZC
> Amarillo, TX
>
> _______________________________________________
>
> 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@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
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.
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