Check the internal potentiometer resistance reading at the ground as the
rotor turns through its full rotation. There should be a smooth change from
zero ohms to around 500 ohms measured the between the pot slider and ground
(pins 2 and 3, respectively on my G800SDX) as the rotor turns. Your pinout
might be different.
I found a somewhat similar problem due to a build-up of insect debris and
moisture inside the backshell of the connector at the rotor. The debris had
caused a leakage path between one of the motor drive lines (4&5, in my case)
and one of the pot connections, so that DC applied to the motor on pins 4&5
showed up on one of the pot terminals (can't remember which one). The
resistance reading on the ground varied wildly, especially when the thing
was turning (duh), and the fix was to clean out the backshell, fill with
non-conductive grease, and seal the whole connecter, not depending on the
rubber boot, which sealed well on the rotor end, but fit loosely around the
rotor cable letting the critters and moisture in. I used Vaseline to fill
the shell, but a purist would find something better, I'm sure. That was
three years ago...been trouble-free ever since.
Your problem might stem from a different source, but checking the resistance
reading should at least isolate the problem to either the
rotor/connector/cable or the controller box.
----- Original Message -----
From: "Doug Rehman" <firstname.lastname@example.org>
Sent: Tuesday, March 28, 2006 7:38 PM
Subject: [TowerTalk] Yaesu Rotator Problem
> First, thanks to all, especially Gene AD3F, for the info on the CushCraft
> D40. FYI, with the D40 set for 7100, the resonant frequency at 8' was
> 22' was 7068, and 65' was 7100.
> I have a Yaesu G1000 rotator with a G800-S controller. When I put the
> combination up last year, it worked perfectly; it recently developed a
> problem. The pair is set up with south center and the overlap from south
> west. From south to south, the needle moves at a varying speed and does
> accurately report the rotator's position; it is accurate at when the
> is at south (either the counterclockwise stop or when passing through
> going clockwise into the overlap area). At the clockwise stop (due west),
> the needle points south-southwest.
> Any ideas?
> TowerTalk mailing list
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