[TowerTalk] Odd T2X behavior

[Kimberly Elmore]

I have two T2X rotors and just replaced one that jammed with one I have recently rebuilt, complete with a new direction potentiometer. All was well until a couple of days ago, when I noticed that approaching the CW end of rotation, I couldn't get a direction indication beyond about 160 deg yet, when the brake disengaged, the direction indication went to 180 deg. Playing with it some, the problem has worsened such that I don't get a good direction indication much south of about 120 deg or so, though it clears up when the brake is disengaged. I initially thought it was contaminates on the wiper arm, but the change in direction indication is so consistent with brake actuation that I am no longer confident that contamination on the wiper arm is the problem. 

The rotor has the AMP connector installed and tested good on the ground. I'm using a Green Heron RT-21 controller. 

I'm beginning to suspect either a bad connection in the ground pin of the rotor. After insuring that the basic resistance checks yield nominal values, I plan to go up and visually inspect the connector and plug. An "out there" scenarios is if, for some reason, the internal common ground developed a problem under brake activation (due to excessive, but not outrageous, resistance) brake current could be divided between a poor ground and the the grounded wiper of the direction potentiometer, yielding both a burned up direction potentiometer (at least on one end) and strange direction indications. Has anyone ever seen problems with the *internal* grounding of the T2X or a direction indication vary considerably related to brake actuation? 

Kim N5OP