[TowerTalk] Identify Remote Rotary Antenna Switch

W0UN -- John Brosnahan shr at swtexas.net
Sun Nov 6 08:57:29 EST 2005


Sounds like it might be an old W0MLY switch with a Ledex drive.
The "motor" is a Ledex mechanism that jumps to the next position
when it is hit with a voltage.  The phenolic switch is what controls
when it stops.

Someone took over the building of these after Dick got too old to
do it anymore.   Might have been the early days of Antenna Mart
and later Max-Gain Systems.

Obviously a photo would help identify it.  I made a copy of one
many years ago and I just ran across it.  It would show my version
of the thing.  The only bad thing is that when the control wafer is
making/breaking it is sparking so there is a burst of RF noise
that some RR choke may help to eliminate.

I'll see if I can dig out mine this morning and shoot a photo of it.
That way you can see whether my Ledex looks like yours.   The
Ledex is sorta the precursor of a stepper motor.


A little bit of research turns this up

Apparently it is no longer made.   The original W0MLY version was
a bit cruder.   But this will give you a bit of an idea to see if I am onto
the right track.

At 07:37 AM 11/6/2005, you wrote:

>One of the things I picked up at a recent hamfest is the remote head
>for a rotary antenna switch. The switch is nearly 6" square, although
>one side is only 4". It has 6 SO-239 connectors and a terminal strip
>with 8 terminals.
>Opening it up, it has a conventional ceramic wafer switch switching
>the SO-239s, an additional phenolic wafer that attaches back to the
>terminal strip. The rotary switch is driven by what looks like a
>phonograph or clock motor through a geared reduction.
>I'm guessing this unit takes 25-30 vac to run the motor, which then
>stops when the correct detent is chosen. As I don't have the control
>head, I'd appreciate any information on this type of switch. I figure
>I can build a control box pretty easily with the right info.
>Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
>Quote: "Not within a thousand years will man ever fly!"
>              -- Wilbur Wright, 1901
>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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