Do you have a couple of batteries straped to the back of your transmitter also. It only has one battery. If it dies ,good by plane.

Yep. At least with my models. However, if my ignition goes nuts I'll still be able to land the plane since the rest of the radio would be working fine. I don't need a running engine to land.

My professional stuff has multiple power (and comm) redundancies on both ends of the tx/rx circuit, including self power generation. Your not bantering with some amature, inexperienced modeler.

What kind of redundancy do you use with your transmitter?

You failed to accurately read my previous. My models are just like yours, with a single source point of failure at the transmitter. Hopefully that was clear enough that time. You don't have need to know with the professional stuff.

The power source loads the coil the signal tells the coil when to fire. The stored energy runs up the wire to the spark plug and fires the plug. About a hundred years ago someone figured out which direction the coil would send the pulse. If they didn't, starting your car would be a lot more exciting. Now, with these cdi ignitions if they are fired without a looped ground the signal gets zapped and blows the pickup sensor instantly and shuts down. Either someone forgot how to wire the coils for polarity or they figured the system would shut down imediatly should it go haywire.
So far there's no reason stray signals should run back to the supply side battery.
About the only long term problem I see is not having a battery with enough oomph to send a strong steady feed of power to the cdi. Where the high frequency bumps the coil/s are drawing from the battery might set the rx to see the power fluxuate at a frequency that disrupts it's opperation.

Only an inexperienced speller...Amature ?

I've got a gas heli and 1/4-scale sprint car, both have G23's and both have had unexpected RF issues causing potentially dangerous situations. Saving a couple ounces weight on a 14 lb. model is not reasonable IMO. Don't ignore the wisdom offered here! No reason was given for using the device - weight-savings, lack of room, complexity?

While troubleshooting my problems, many said to 'go 2.4, or PCM' which might have worked but would have been masking the problem. Once the RF problems were fixed, there was no need for those band-aid approaches. Good point on the brown-out issues, too. Plenty to ponder, podner.

Ed

Sometimes in a hurry to get onto something else and didn't proof. You do it too you grumpy #1

Really though, I think we all too often grab stuff in the hopes they will become panaceas for generaly minor problems, or things that are not problems at all. We also seem to make it a point to glom onto new stuff simply because it's new stuff. Looking at a larger picture, we haven't eliminated the threat of electrical noise feeding back to receivers from simple outrunner motors yet either. If there's a way for EMI to find a path to servos, it will if the strength is high enough.

Just excersise a little caution with these things because you're betting the bank, and the one's belonging to those around you, when electing to choose a different path.

I have a 6v and a 4v from tbm, no issues yet.

I have a 6v and a 4v from tbm, no issues yet.

Nicads!! Good Grief!!! I've been flying them in my planes for 40years and I never realized how dangerous they are. All seriousness aside,
I'm in the computer business and people who have to have the latest technology are my favorite customers. There is nothing wrong with the latest and greatest but when it comes to multi thousand dollar planes with the potential to do serious damage I tend to err on the side of being conservative. Charles Lindberg wrote in his book "The Spirit of St. Louis" that his backers wanted him to use a three engined plane to fly across the Atlantic. He convinced them that three engines meant three times the possibility of failure and were actually less safe than one. This still applies to technology, the more gizmos it takes to do the same job the more chance of failure. My philosophy in setting up my warbirds, racers, sport planes is KISS. I know that newer flyers will poo poo that but I've seen lots of newcomers come and go in this hobby and I am sure it will never change. By the way, I am going through this exact argument with one of the newest members of our club. I am helping him set up his 1st warbird and he wants to fill it up with multiple battery packs running both the radio and ignition and power buses and super switches and the latest this and that and cameras and just about every other electronic gizmo known to man.


Larry

I was gonna drop the subject but I have to rebutt this one.....

Really?? You are implying that you get certification from every other manufacturer of items you use in models, that these items will "be absolutely free of unwanted responses to-, or passing white noise RFI disturbances to other devices"

Then you further state "I have not seen such certification, and until I have, will not advise anyone to use it directly (galvanicly) connected to any onboard radio receiver".

The question that immediately comes to my mind: Do you even attempt to fly ANYTHING in this hobby? What assurances do you get from everyone else that make you feel secure enough to make an attempt? Radios, engines, airframes, whatever....

Some have been in the hobby and associated fields for a very long time and have learned not to trust everything they see. They understand that risk is not restricted to the owner of the plane, and have learned to respect liability. Some of those same people have provided much of the background testing that established what did, didn't, would, or wouldn't work.

Myself included. Reason why long timers in the sport should, must, educate those with lower tenure

Anyway, I think the original poster got what he needed from this diatribe. Unsubscribing

The designers never have to clean up their own mess. That is why they do stupid things to save weight and why they never seem to learn from that smoking hole they just made. I remember 20 years ago seeing "gas snobs" crashing a couple of lifetimes worth of fuel savings before they figured out RFI.

Our radios are certified, so are the receivers.
They are howevernot certified to resist high RFI levels from other interference sources.
Ignitions also are not certified to high levels, that is why NO ignition manufacturer in his right frame of mind sells his ignitions without the statement that they are for model airplane use only, and that the user should keep a certain distance between the device and radio gear.
Now, I wonder why they do that?
I also wonder why some *heads find it safe to ignore that warning.
I cannot stop wondering if I see people actually promoting the ignoring of the warning.

You know my standards. Doesn't matter what else you do, range test engine running and off. Compare distances and make the decision.

What he say.
Grumpy

RCEXL ignitions ARE certified as 'gas engines ignition system'.
Test Standards:
EN 61000-6-1:2001 Electromagnetic compatibility, Generic standards . Inmunity for residential, commercial and light-industrial environments.
EN 61000-6-3:2001 / A11:2004 Electromagnetic compatibility, Generic standards, Emission standard for residential, commercial and light-industrial environments.

See the complete certification report here :
http://www.rccdi.com/upfile/200992/2...9562225876.pdf

Not high RFI levels , but ...... interesting.

Regards

That's right Manuel. This certification allows the ignition to be used in a sensible way.
Shielding damage should also be taken into consideration for airborne RFI. But this discussion is about galvanic coupling through the cable harness when the ignition is plugged into areceiver channel.

What I say is to do a lot of range testing with some person to help. Then if everything works good...get a fair amount of flying in to make sure no bad stuff happens. I fly most of the time where there is nothing to hit anyway...do not want to hit a person for sure. I do not fly much at fly-ins...don,t care too show off. But I can fly good...too prove it I willhavevideo made & post it some time this summer. Best Regards & smooth landings.

Capt,n

Wouldn't a simple AM radio be able to pick up whether or not an ignition is casting stray RF? I'm no electrical wiz but it seams an enterprising feller could sell a bunch of units that could detect whether or not an ignition is running dirty.
Think I'll grab the lil sony pocket am/fm radio and test my stuff this weekend and see.

The television is a good test device.
So is range testing and watching for glitches when the engine runs or the ignition is operated by a test device like RCexl has.

If one uses Single Point Ground (SPG) practice by having two leads coming out of the battery, I do not see a problem as I do it myself in 3 different setups. It takes surprisingly minimal inductor capacitor (LC) filtering if at all to quench any voltage ripples (conducted emission or CE referred to in EMI/EMC testing). Besides, the capacitor discharge ignition that we use empties the stored energy after every spark since it uses a self-commutating SCR (silicon controlled rectifier) to fire the plug. The harmonics that cause electrical noise is very minimal.

I have looked at noise caused by high voltage discharge ignition and noise caused by metal to metal scratching on my scope. Metal to metal scratching is one order of magnitude worse. It will make servos jump or cause a fail safe in the receiver. Whereas, having continuous spark from an open face plug placed next to the receiver did hardly anything to the received rf.

Hmmm.
I had my battery charger randomly switch on and off when testing an ignition with damaged HT wrap, such was the magnitude ofradiated levels.
Distance between DUT and charger was about 1.5 meters.