Interference and 2.4GHZ
#26
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What about this Ace. One of my buddies had the ignition switch and receiver switch side by side with a few inches of wire from each running parallel and close to each other. During the ground test his servos would twitch every now and then. After I kicked him in the *ss he went home and arranged his installation the “right” way. He had no problems after that. Another guy had his receiver regulator and ignition regulator side by side with the wires also parallel and this time tied together. It worked for a while but the day I was there his system went into fail safe and then the ground. As we collected the pieces he explained to me what he had done and felt that it was all right since it had worked for some time. Dan.
#27
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I was just saying that with all the technical jargin going on maybe it needs to be pointed out it is not a "HIT" on the radio. It is a hit on the internal system. Yes the electronics operate on a much lower frequency, 200-250hz, so it is very easy to have interference if anything is improperly installed, such as a loose cap. I'm sorry but I feel that most whom have these type of issues assume it is the radio when in fact it is something else, totally something else!!
#28
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I'm not getting into a pissing match over this because I have no issues and never have. All my planes have switches side by side, those Miracle switches, and not one issue but I also have a filter by way of a IBEC on the ignition between it and the switch. Now as for the regulators side by side, lol, that's just dumb. And as others before me have said, I am out of here. You all have fun figuring it out.
#29
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I can't speak electronics talk but can tell about an experience at the club field. The guy had an Evolution 15 engine on a 4 Star 60 with a Spectrum radio. When the engine was started, the servos starting jittering especially the throttle. After the engine was shut down we discovered that the plug wire was over the plug but not turned and locked. I pushed the plug wire further down on the plug and turned it 1/8 of a turn to lock it on. The problem went away. My conclusion - - - it is possible for an electron ignition to mess up the operation of a 2.4 radio.
#30
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Ok time to throw out my 25 cents worth. First off I think I have a unique advantage here. First off I have been flying R/C for 36 years. So I have used all types of systems from the old AM stuff to FM, FM narrow band, PCM and now SS. I have also been professionally building RF equipment for 15 years and currently build aircraft antennas of all frequencies that end up on military aircraft. I at times work with our R&D department not only building antennas but building test rigs that go into the chambers to simulate what affect the aircraft will have on said antenna.
That being said to a certain point I agree with Dirtybird and think that Ace has a great perspective on what is happening. For ignition generated RF to swamp a 2.4 RX it would have to be a significant amount of power. Most ignitions draw approx 1 amp at full throttle. The input power going into the ignition just would not support enough power to swamp the RX. Even if it did, the system would go into Failsafe. What we are seeing is glitching. This clearly means that the stray RF is coming in somewhere other then the RX. The signal wire of any servo lead can act as an antenna and transmit RF into the servo. This is what we are seeing. This usually only happens when something is amiss with the ignition. A loose cap, chaffed grounding braid on the wire, too large a gap on the cap seam could all cause this issue. IMO as long as the ignition is working as designed then there should be no way it can create issues with RF.
That being said to a certain point I agree with Dirtybird and think that Ace has a great perspective on what is happening. For ignition generated RF to swamp a 2.4 RX it would have to be a significant amount of power. Most ignitions draw approx 1 amp at full throttle. The input power going into the ignition just would not support enough power to swamp the RX. Even if it did, the system would go into Failsafe. What we are seeing is glitching. This clearly means that the stray RF is coming in somewhere other then the RX. The signal wire of any servo lead can act as an antenna and transmit RF into the servo. This is what we are seeing. This usually only happens when something is amiss with the ignition. A loose cap, chaffed grounding braid on the wire, too large a gap on the cap seam could all cause this issue. IMO as long as the ignition is working as designed then there should be no way it can create issues with RF.
#31
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Truckracer;
The received signal strength has to be well above the on frequency noise floor or all bets are off even for 2.4 GHz.
That used to be the case but not with SS. The signal can be as much as 40db below the noise floor and be detected.
This is the reason we need only 100 mw to do the job we needed as much as 2W to do the job on 72 even though the path loss is much higher on 2.4 than it is on 72. Check it out.
The received signal strength has to be well above the on frequency noise floor or all bets are off even for 2.4 GHz.
That used to be the case but not with SS. The signal can be as much as 40db below the noise floor and be detected.
This is the reason we need only 100 mw to do the job we needed as much as 2W to do the job on 72 even though the path loss is much higher on 2.4 than it is on 72. Check it out.
#33
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Well two posters seem to grasp what I am trying to point out, speedracerntrixie and acerc.
If you have a problem its not the 2.4 system. It could be a battery,a switch or servo or even just an intermittent contact.
Those could reduce your toy to matchsticks then you will go around saying that (fill in the blank) system failed me.
If you have a problem its not the 2.4 system. It could be a battery,a switch or servo or even just an intermittent contact.
Those could reduce your toy to matchsticks then you will go around saying that (fill in the blank) system failed me.
#35
RF noise is transmitted through the wireing, often caused by a poor ground of the spark cap but that is not the only place it will come from. High frequency vibrations from metal to metal components create RF noise also and they find their way into the wireing and effect the servo signals on analog servos and can cause pulses (twitching if you like) digital servo signals are not effected by RF noise nor is the radio reciever. Keeping the seperation of ignition wireing from all other wireing as well as proper isolation of metal connections will eliminate most of these problems along with the proper servo selection in close proximity to engine modules. This is not a point to argue about, you can't argue facts.
Leroy
Leroy
#36
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This isn't igntition related but close enough to add here. There is another thread on FG about leaving the WiFi turned on with onboard gopro cameras and many, many crashes resulted from it. The theory seems to be that because the GP's WiFi transmitter is so close to the RX that it effectively swamps the entire spectrum and causes loss of control. A few FPV'ers chimed in with similar stories about quads doing similar or wacky things when the WiFi is turned on. I'd be interested in hearing the experts opinions on this and whether or not it relates to the topic here.
#37
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This isn't igntition related but close enough to add here. There is another thread on FG about leaving the WiFi turned on with onboard gopro cameras and many, many crashes resulted from it. The theory seems to be that because the GP's WiFi transmitter is so close to the RX that it effectively swamps the entire spectrum and causes loss of control. A few FPV'ers chimed in with similar stories about quads doing similar or wacky things when the WiFi is turned on. I'd be interested in hearing the experts opinions on this and whether or not it relates to the topic here.
#39
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I'm going to agree its outrageous...
why, 2 days ago...
inadvertently loosened the spark plug cap while the engine is running... observe control surfaces go nuts, tighten spark plug cap back up.. observe control surfaces return to normal control....
This was with a $600 2.4Ghz radio....
when its setup properly I agree, I've had 0 issues with gas and 2.4ghz... but if things get loose all hell can break loose...
why, 2 days ago...
inadvertently loosened the spark plug cap while the engine is running... observe control surfaces go nuts, tighten spark plug cap back up.. observe control surfaces return to normal control....
This was with a $600 2.4Ghz radio....
when its setup properly I agree, I've had 0 issues with gas and 2.4ghz... but if things get loose all hell can break loose...
#40
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I'm going to agree its outrageous...
why, 2 days ago...
inadvertently loosened the spark plug cap while the engine is running... observe control surfaces go nuts, tighten spark plug cap back up.. observe control surfaces return to normal control....
This was with a $600 2.4Ghz radio....
when its setup properly I agree, I've had 0 issues with gas and 2.4ghz... but if things get loose all hell can break loose...
why, 2 days ago...
inadvertently loosened the spark plug cap while the engine is running... observe control surfaces go nuts, tighten spark plug cap back up.. observe control surfaces return to normal control....
This was with a $600 2.4Ghz radio....
when its setup properly I agree, I've had 0 issues with gas and 2.4ghz... but if things get loose all hell can break loose...
There are a lot of other things that could cause that.
#41
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Preconceived reasoning or whatever, it really doesn't matter. There was a noted cause and effect and the radio system was affected. Fixing the offending part resolved the issue. What more matters?
Many people have pointed this and similar cases out to you but you continue to blindly ignore everyone while spouting more dribble.
Last edited by Truckracer; 08-20-2014 at 10:07 AM. Reason: Not smart enough to leave this thread
#42
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Truckracer,
It's like explaining to the wife why the analog tv won't pick up any of the digital channels no matter how hard she tries. If they don't get they by now, they ain't gonna get it!
It's like explaining to the wife why the analog tv won't pick up any of the digital channels no matter how hard she tries. If they don't get they by now, they ain't gonna get it!
#46
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I m sorry about your head badass. How did you manage to pry it out of your---?
I guess its time to leave when people start shouting and calling me names.
I hope some of you readers of this thread will check a bit further when you encounter such a problem. It might just save your aircraft.
I guess its time to leave when people start shouting and calling me names.
I hope some of you readers of this thread will check a bit further when you encounter such a problem. It might just save your aircraft.
#48
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Certainly curious people can dig deeper into the matter where others could care less as long as their pride and joy returns to earth in one piece after every flight.
#49
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You are still not convinced?
Try this:
Remove the spark plug from your engine. Remove propeller and spinner.
Insert the spark plug in your high tension lead.
Install the spinner on your engin without the propeller, turn on the ignition, and the receiver and transmitter, and use the starter to spin the engine. Have someone else operate the controls and hold the sparking plug as close to the receiver antenna as you can.
You will find that your system will operate normally.
Try this:
Remove the spark plug from your engine. Remove propeller and spinner.
Insert the spark plug in your high tension lead.
Install the spinner on your engin without the propeller, turn on the ignition, and the receiver and transmitter, and use the starter to spin the engine. Have someone else operate the controls and hold the sparking plug as close to the receiver antenna as you can.
You will find that your system will operate normally.
I like that your trying to help people, I don't understand the point your trying to make though....gas ignitions can be problematic for people... when you have them you have to go through your system 1 item and a time and figure out what that problem is, otherwise you probably won't like the result....