futaba1024

Hi Guys.
Did not know which board to post this so will start here.

Have just done a first motor start on a pals CMP Cessna 182 with Zenoah G26ei and Spektrum DX7/AR7000 rx and all hell broke loose on half of the chanells when the motor started.

The elevators (2 servos mixed on ele and aux2), gear and aux1 all glitched terribly when the motor fired and got worse as the revs increased, you can even make them glitch just by turning the motor over by hand with the ignition on as the hall sensor is fired.

The throttle, ailerons and rudder chanells are not affected, they solid as a rock.

Have a feeling we may have a dodgey rx, any ideas?

rhd-RCU

My Feedback: (36)

Make sure you have a resistor plug. Have seen this happen when a non res. plug was used.

airbusdrvr

I don't fly gas but a friend had a new gasser go nuts when he first ran it. I remember one of the gas flyers pointing out that he had a metal push rod to the engine throttle. When the metal was replaced with a nylon(sullivan golden rod) rod it settled down.

SunDevilPilot

Is the plane equipped with two completely independent power systems, ignition and radio power? Make sure they are in no way connected........

SunDevilPilot

futaba1024

Well this is all a bit embarrassing .

All this talk about suppressors and plugs caps etc, remember thinking when I fitted the plug cap that the internal clip did not make contact with the plug and there was an air gap. (i know I know)

Knowing that some HT systems do use an air gap to increase the spark power.........Thought nothing more of it, until this morning.

Just been down to the workshop and pushed the plug cap a lot more firmly onto plug and click I heard the connection clip home.

Heh presto no more glitching ;.

Thanks very much for your input guys. (futaba1024 about to fall on his sword!)

colecaz

Thanks for posting the solution. Spark gap transmitters went out of style a LOOOONG time ago.