catboater

My Feedback: (51)

Danny, We have a 1/4 scale Extra 300 with a MDS 1.48 2-stroke glow engine for power and a JR 549 rx. The tx is a 8103.
For some reason we get intermittent radio hits while flying. It can be any control surface at any time. They are very short glitches and so far we've been lucky that nothing bad has happened, but they are driving us crazy!
I have changed receivers and crystal and also tried a different rf module but nothing has helped. We've double checked all of the usual suspects such as metal to metal on the throttle or the pull-pull cables being crossed and I've even swapped out the rudder servo. It still glitches.
The servo's are all Hitech digitals except the rudder and throttle.
The engine really vibrates and I'm wondering if the vibration could cause glitches. The prop is balanced and the spinner is true.
The 8103 was sent in to your place back in March for a check up and new lithium battery. I also had the rf module tuned to ch 21.
My son is flying in a contest next week so I'm getting pretty desperate. Can you help?

Thanks very much!
Chris

dsnyder

Vibration can cause issues, it may be a good idea to increase the amount of foam around the receiver etc. Unfortunetely the number of possibilities in a case such as this are numerous. This could be outside interference, model generated RF, harmonics with other radio signals, etc. Have you tried using another channel? Have you tried the model in another area, 20 miles away or more from the area you are having a problem? How much range are you getting with the system in a range test? Does the range change significantly with the engine running vs not? If so, it could be a bad bearing in the engine. It is possible that a PCM receiver could help reduce the chance of a hit. Also adding a filter on say the throttle servo lead, the lead from the switch to the receiver, and any extensions over 36" could also help. These filters are part number JRPA028 and JRPA029.