xlr82v2

My Feedback: (1)

My Power Panel glow driver is causing radio interference while starting the engine.

Any suggestions how to solve the problem other than using a NiCad glow driver?

Thanks!

JohnW

My Feedback: (6)

They do that sometimes. As long as your are 100% sure it is exclusively related to the glow booster, you are fine, i.e. booster isn't attached during flight.

bob_nj

My Feedback: (62)

It does happen, don't worry too much about it. Certain receivers seem more prone to it than others. Which do you have?

Ladyflyer

My Feedback: (2)

Get a different power panel . It could cause problems in the pits .

bob_nj

My Feedback: (62)

Normally the driver has to be connected to give the "jitters"

causeitflies

Tighten up the plug connections on the panel (splay out the banana plugs) and at the glow plug. This will help but you still may get some jitters.

branded

My Feedback: (9)

DITTO! I've seen this phenomena many times. Nothing to worry about.

strato911

Since I've never witnessed this (most pilots use NiCd glow starters), can you tell us the approx. radius around the box affected by this phenomena? I hate to see someones complacency shoot down a fellow flier...

branded

My Feedback: (9)

Whoops...Double post

causeitflies

A loose fitting glow starter will make intermittent contact with the plug and put out enough of a signal to cause glitches because it is in close proximity to your receiver. Once you take it off does it stop? If this is the case it is a common occurrence.

bob_nj

My Feedback: (62)

It only affects the plane it's attached to. It's not anything like an RF field or transmission of any kind.

xlr82v2

My Feedback: (1)

Yep. Only when the glow driver is attached to the plug... if you remove it, the jitters stop. Also, once the engine is running, the jitters seem to stop also.

I have 2 recievers that have problems with the power panel. One is a Hitec, and the other is a Futaba 127. The Hitec reciever has real problems with it... servos will go to the limits and try to go more. Not good . The Futaba just gets the jitters.

I'm wondering if putting a choke or filter in the wire would solve the problem.

JPMacG

My Feedback: (2)

Its caused by the pulsed waveform of the power panel. These power panels put out 12 V pulses rather than pure DC. Pulses have lots of harmonics, all the way up and past 72 MHz.

You can probably calm it down by putting a bypass capacitor across the output terminals of the power panel to smear out the rise and fall times of the puses. Something like a 0.1 or 0.01 uF disc ceramic. They are available from Radio Shack I expect. Don't use too large a capacitor or you might possibly overdrive / burn out your glow plugs.

bob_nj

My Feedback: (62)

Yeah, what he said

Ladyflyer

My Feedback: (2)

Some power panels will not tolerate a capacitance across the output . It could alter the output pulse width . Any stretch could easily burn out a plug or three.
If planes taxi in the pits where you fly (I know they shouldn't) it would be best to play it safe. Any one CAN take chances and most even "get away with it " Whatever suits your style

Lynx

The pulsations are local only, they're not radiated. Pulsed DC will do this because it changes the radio's perception of what ground is which causes it's perceived signal to jitter, even though the signal itself is staying constant. RC systems are designed to be closed loop, they're not designed to take into account the entire electrical characteristics of what's connected to it. Don't worry about it.

Ladyflyer

My Feedback: (2)

The pulsations are indeed "radiated" . The range is limited but it is electromagnetic radiation. A different panel of the same type probably would not have the same affect .
I would replace a panel generating interference ,but I prefer cheap insurance over being "cheap" .

The servo jitters from disconnecting a glow plug or a loose connection are also electromagnetic radiation but ARE normal and no cause for concern.

Lynx

The frequency and power are so low you would only be able to pick up the signal a few feet from the emission, a random piece of wire and a pulsating DC signal are not an ideal RF emitter which is why I don't consider it a possible cause for RF failure outside of where the interference is actually occurring. Human beings actually put out enough energy to be picked up in those situations, if you hook em up right <G>

mr_matt

My Feedback: (10)

How then do you think the interference is getting to the reciever on the plane then??


Of course they are radiated. The question is how far. If they are strong enough to interfere with the guy next to you and it happens to affect his throttle when he is taching his motor....?

Lady Flier said it best, you takes your chances, some do and some don't.

xlr82v2

My Feedback: (1)

Yes, it has to be radiated.

There's no metallic connection between the engine and the servo (or the reciever for that matter.) I always put a short section of nyrod in my throttle pushrods to isolate the engine and the throttle servo to prevent interference.

I've noticed it gets worse as you bring the electric starter motor up to the engine to start the engine. So obviously there's some backfed RF coming from the electric starter also.

I think that the radiated range of the RF interference is probably in the neighborhood of 24 inches, on my airplane.

Ladyflyer

My Feedback: (2)

Yes, it has to be radiated.


Exactly

A few years ago we had a plane with an uncontrollable throttle every time the flier NEXT to him connected his glow driver. It had an affect on the plane it was hooked up to as well . Moving the plane another 24 inches eliminated the interference . The power panel generates no interference when it is not connected because the current flow is negligible . Once connected a noisy component can cause problems.