[TowerTalk] CDE HAM II Rotor . . . another question

[Steve]

Several of you were kind enough to help me a few weeks with a question 
about a CDE HAM II rotor. Now I have another issue and thought I'd try 
my luck again.

I bought this CDE Ham II rotor in 1976, used it for about five years and 
removed it from service and stored it.

The problem I'm having is with the direction indication on the control 
unit. If the rotor starts at full south and I turn it in the SENWS 
direction, it seems to work ok. But if it's full south and I turn it in 
the SWNES direction, the indicator meter on the control unit stops at 
about 270 degrees even though the rotor is still turning. When the rotor 
gets to about 360 degrees, the meter jumps to the correct indication and 
works ok through the rest of the travel to south. So the indicator meter 
works OK in one direction but not the other.

I thought there was a problem with the potentiometer assembly and so 
bought a new one from the Hy-Gain people at Dayton. I replaced it and 
learned that the new potentiometer assembly exhibits essentially the 
same behavior as the old one :(

With the top casting removed the potentiometer assembly is readily 
accessible and easily turned by hand. I see the same 270-to-360 jump 
when turning it by hand.

Where do I go from here? Two defective potentiometer assemblies? It 
seems like pretty long odds that a potentiometer assembly from 1981 
would exhibit the same anomalous behavior as a new one I bought this month.

Any advice out there?

Thanks.

Steve