So I installed my Scherrer system and got everything set up, and noticed an interesting problem.
On first testing, I noticed the ailerons acting very jerky but the rudder/elevator were nice and smooth. As I was testing I noticed that the RSSI level on the Rx dropped any time I was moving the ailerons, but stayed locked at 100% for any other control surfaces. The only thing I can think of is that the elev/rudd servos are HXT900's, and the ailerons are Corona 939MG's.
Did you run the AIL servos leads through a filter to see if you can clean it up?
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Not yet, just noticed the issue tonight. Figured I would post up to see if anyone's had similar issues. It's a dual aileron setup on a Y harness, not two independent radio channels. I'll try a ferrite ring, or I could try a full LC filter on the power leads to the servo.
Just not sure if it's feeding back through the power line or if it's the servos themselves creating RF noise.
Resurrecting this thread due to additional information. It seems I'm not the only one who has experienced this, and Thomas Scherrer himself has some valuable insight into it.
Quoting from the "other place"..
WARNING
do not use Corona DS-929MG with the LRS RX,
unless you also add a good and strong capacitor directly on the RX.
Those servoes are designed with a timing fault !!
so the motor driver actually shortcircuit the supply line for a very short time.
I measure 7A peaks at 20uS width,
I can reach any current I want, just feed it power with a lower impedance
and the current rise and rise !!
you can imagine the inductance in your power cable to your good and stable BEC
will drop the voltage several volts at this high speed, causing the RX to be jammeded
due to low under specification input voltage.
My best advise it not use use such badly designed servoes at all
those current pulses will cause you alot of trouble
when combined in a long range fpv system,
how ever it is possible to stabilize the voltage and remove the jerking movements
by adding a 2200uF/16 directly on the supply rail of the rx,
if you use several such servoes, you do the math,
the peaks are NOT in phase with incomming servo pulse !!
so sooner or later they will colide and your peak current will be doubled and so on.
Any other digital servo that is correctly designed will NOT draw such short and high peaks.
oh by the way this warning also apply to some types of hyperion atlas servoes,
so it is not easy to say if it is expensive it is designed correctly.
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