Nick C

I heard along the grape vine that wrapping your reciever in aluminium foil was a good thing in that it prevented interferece entering your reciever directly, i.e. you are installing your reciever in a faraday cage.

Does anyone have experience of this?

Would it not also prove benficial if you were to wrap your servo leads, I've got some long ones at the moment, in foil to prevent them picking up interference and feeding your reciever.

rajul

My Feedback: (58)

Will there be any risk of metal noise if some parts of the loose foil are rubbing under vibration ?

Nick C

yep thats a very good point, I had not thought of that. This noise might very well cancel out the suppresed interference.

I suppose you could get all fancy and cut a square block of foam with your reciver installed in it and then very carefully glue foil to the outer sides of the square block, mind you, you still need to electrically connect all 12 edges without any rubbing,

hmm is it really worth it?

patternwannabee

My Feedback: (1)

What about twisting your servo leads?

Would that reduce interference on long leads?

rajul

My Feedback: (58)

Nick, modern receiver designs with advanced filtering techniques are quite reliable, providing the basic radio system installation "guidelines" are adhered to. IMO wrapping aluminum foil may do more harm than good. Which receiver are you using ?

smokingcrater

first of all, are you having a problem with interference? nothing to fix if you aren't having a problem...

JPMacG

My Feedback: (2)

I think you are on thin ice here. The receiver circuit board, servo leads, and battery leads form part of the antenna system. If you place them in a shielded box the receiver may lose range.

Nick C

I am using a futaba R149DP, and I am not currently experiencing any interference, (it hasn't become airborne yet).
It is my first jet and I am just investigating ideas for improving the reliability of it , what with half a house morgage flying about up there.

I have installed a opto isolater in the radio system, from the recommendation of other jet jockeys who seem to be very concenered about interference and I heard about this method (reciever foil wrapping) at a jet meet.

dirtybird

My Feedback: (5)

Many years ago the manufacturers of radios decided that putting a receiver in a aluminum case was not required either from a mechanical or electrical standpoint. Why do you think the fellows at your field know more than the maker just because they can fly a jet?

SMALLFLY-

My Feedback: (19)

If you think about it wrapping your reciever while leaving the antenna hang out of it is rediculous. any noise will be picked up by the antenna and transmitted directly, that's what it is supposed to do. shielded servo leads are another matter, having no external component to pick up noise I really dont know why someone isnt selling shielded servo lead extensions, Are they required no, but people buy lots of expensive stuff for giant airplanes and jets "hoping" it will make it better-more reliable.

dirtybird

My Feedback: (5)

The antenna is connected to a tuned circuit that will reject unwanted noise, however the reciver has internal bypasses an inductors that prevent spurious noises from entering. This make external shielding and other tricks mentioned on this BB unnecessary. Thats why they don't bother to shield the servo wires or twist them. We need to progress from the dark ages of this hobby.
What is truly needed for large powerful airplanes is a totally redundant system that provides two independant RF paths to the airplane in case one fails or is interferred with. Or as someone else suggested a spread spectrum system.

patternwannabee

My Feedback: (1)

Hi Dirtybird,

I did witness some kind of interference on a plane with an ignition engine, or at least it seemed that way to me. With engine stopped, control surfaces were steady. With engine on, they moved around spuriously. Some long servo leads were on the plane.

In this case, apart from a redundant system, what can be done?

SMALLFLY-

My Feedback: (19)

interesting way to agree with me (I think)

dirtybird

My Feedback: (5)

Fix the ignition shielding. Get a resistor spark plug. Playing with the servo leads won't help.

patternwannabee

My Feedback: (1)

Good to know. Thanx

JPMacG

My Feedback: (2)

If you do go the Faraday cage and shielded cable route, make sure you connect the cage and shielding to the receiver ground. Otherwise you are likely to affect your antenna performance.

dirtybird

My Feedback: (5)

The trouble with shielding is you WILL most likely affect your antenna performance. Your receiver has been tuned without it. Adding all of that extra metal could detune it. And you could create reflections and dead spots.