[TowerTalk] CDE AR-40 Oddity

Mike Clarson mclarson at rcc.com
Wed Jul 16 01:24:24 EDT 2008

Mark: First, let me say I am no expert on these units, but I have some
familiarity and have brought some back to life. It sounds like you have an
AR-22 unit, not an AR-40. Similar units, but the 22 uses a 4 wire control
and the box clicks, while the 40 uses 5 wires and, I do not think it clicks.
Briefly, the way it works is there is a cam geared to the motor, which
closes a switch momentarily every 6 degrees of rotation, or 60 clicks from
stop to stop. If the clicks come regularly and there are no double clicks,
someone had to mess with the innards of the rotor. I don't know if it is
even possible to do what you say by changing the insides. Maybe this is the
problem: Is the control box a CDE or an Alliance? Alliance made a similar
rotor. It looked completely different, with mast passing through the rotor,
but it worked similarly. Model U-100. One major difference was that it was
designed to click every 10 degrees, or 36 clicks stop to stop. If you have
an Alliance box, and point it from North to South, the box will click 18
times for the pointer to move 180 degrees. The rotor will also have moved 18
clicks, but in 6 degree steps, or only 108 degrees, 72 degrees short of
where the box says. Voltages are a bit different, but the boxes do operate
the rotors but with messed up direction indication. If you decide to take
the unit apart, watch out for the ball bearings coming out when you separate
the case. Good Luck, Mike, WV2ZOW

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of butwheat
Sent: Monday, July 14, 2008 10:04 PM
To: towertalk at contesting.com
Subject: [TowerTalk] CDE AR-40 Oddity


I recently was given an old CDE rotor, I'm thinking it's an AR-40, as it has
the familiar bell housing for the motor, but the lay flat on the table
control with the old fashioned clicketyclik as it passes stops.

When given to me I was told it didn't stop at the limits, and that's true,
and I'm interested in that.

I could live with that alone, but now I find that it has another oddity. It
always stops short of where it's been commanded. If I start with, say,
north, and command it to south, it stops 30-45 degrees short. This happens
in both directions and no matter how far it's commanded.

Now THAT makes it pretty useless, eh?

What's up wid dat? Please?



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