[TowerTalk] Emotator Rotator

[Roger Parsons]

I have been using an Emotator rotator and 1105MS controller for quite a few years, generally successfully. However, for the past several years it has not rotated when the temperature has dropped below about -10C.

My first thought was to put in low temperature grease, especially as this had not been changed for many years.This made zero improvement. I then wondered if the connections had gone high resistance. Measurements indicated that they had not, although I wasn't able to measure the resistance of the connector on the rotator. I parallelled several wires in any case, but this also made zero improvement.

Information on Emotator is very sparce, but this one uses 28V AC and the rotator has two windings with a common point. Voltage is supplied between the common point and either one of the windings. There is a capacitor (of unknown value) between the two directional inputs. My latest thought was that perhaps this capacitor was faulty. Looking at the waveforms on each of the inputs show that they both have sine waves (of the same amplitude) with about a 90 degree phase difference, and that this phase difference is reversed when direction is changed. This seems correct to me, but I would much appreciate any other thoughts.

Because I've run out of ideas! Of course, I can't actually do anything about it for several months until Northern Ontario gets a little warmer.

73 Roger
VE3ZI