RAM Beacon causes servo glitching; Help
I am trying to solve an electrical problem and hope someone might have suggestions on how to isolate and fix this problem.
I installed a RAM products beacon, and when I turn it on, the nearby 1/4 scale rudder servo gets the jitters. Turn the beacon off and the jittering goes away.
The RAM beacon operates on 9 volts, with the power going to an electronic gadget which sends the current to the beacon on the tip of the rudder. The gadget causes the beacon light to vary in brightness, simulating a rotating beacon.
The aircraft has three batteries; a 9 volt just for the beacon (and landing lights), 4.8v for the receiver, and 6v for the servos (through a power board). The 4.8 v and 6 volt share a common ground. The 9 volt wiring is fully independent.
The three batteries are all in the nose. Power is supplied to the gadget from there on 38 inch leads (large aircraft). Receiver and power board are also on the ends of 38 inch leads. All three battery leads pass through a half inch diameter hold in a former and then they diverge to end about 4 inches from one another in the fuselage beneath the wing mounting.
The jittering servo is about 10 inches from the beacon gadget on a 12 inch lead from the power box. The receiver is about 4 inches from the gadget, and of course the antenna (72MHZ) runs from the receiver and aft within the fuselage, roughly on a parallel course but 5 inches away from the wiring from the gadget to the beacon.
I have also installed wing mounted landing lights. These are not powered yet. However, the 9v power for that will come from the same battery (no beacon effect) and is switched by an electronic relay (PicoSwitch by Dimension Engineering), located next to the gadget. This relay operates off the a spare channel (landing gear) via the receiver and that relay is powered at this time. (The literature for the switch states that it is a relay switch that offers full electrical isolation).
A second servo operates on the same channel as the rudder servo via a wye connector for nose gear control. It is in the nose, receiving power and signal from the power box on 38 inch leads. This servo does not have the jitters.
Servos are analog.
Troubleshooting so far:
1. Disconnected the relay from the receiver: no change
2. Disconnected the 9v battery in the nose, and temporarily connected the gadget to a 9v battery on 6 inch leads. Jittering was much worse.
That's all so far.
Unplug