Servo jitters/spasms on Kingcat elevator?
 

Anybody else experience really bed servo spasms on their elevators?

HD "y" (no amp) w/ ferrite ring right out of JR 945 RX , about 5' of hd gold extension on each leg of "Y" to both 8611 servos.

I've replaced all wiring with no sucess- if only 1 servo is plugged in it doesn't happen.

Will happen on a 4 cell pack, but really gets bad on 5 cell .

Horizons site says new MOTORS and case tops have been put in the 8611"A"

It happens with nothing else plugged in RX, even with TX turned off (failsafe/hold)

I suspect "crosstalk/feedback" or bad feedback pots between the ele servos- the Horizon tech I spoke to says he hasn't heard of a problem like this.- but he does say not to run greater than 2' extension without amplification-(I know alot of our planes have more than 2' of extensions!)

I'm just not to thrilled about R+R the servos ,shipping and possibly being told "theres nothing wrong with them"

Jake

RE: Servo jitters/spasms on Kingcat elevator?
 

I am familiar with at least two other KingCats with the same setup (except using 955 RX) that have had the exact same problem. For me the solution was to run individual extensions directly from each servo to the RX, using a clamp-on style JR choke on each.

I think the problem is noise related and caused by running two servos on very long extensions through a "Y" and a single choke (on the short leg of the Y), but that's just my guess.

Barry