Hi all,
I just converted my Black Horse Cap232 from 35MHz to 2.4G.
When I ran up the engine I had massive radio interferance.
The Rx was in the same place as the 35MHz one and I had a satalite even further aft to increase seperation from the ECU and the Rx.
I am using a JR 12x Tx and have the aerials on the main Rx horizontal in the same axis as the main wing tube, and the satalite aerials vertical.
I am using two batteries, one for the gear and another one for the engine.
The two batteries are beside each other in the model.

I am using an Evolution Petrol engine.

Any suggestions as to the cause or solution greatly received.

Cheers,

</p>

Big Feet,
I have recently installed a 2.4G into my Telemaster, and the installation is clear when notifying the installer to ensure the Rx antenna are 90 degree from one another. Now I don't know if the sattelite will make this different, but you could try to arrange the antenna leads for the Rx as instructed... tis may clear up the interference. Also, one must use a resistor type plug on a fuelly, when using the 2.4G set up, to curb interference. Give it a go.

Keep you head up on a swivel.
Skratchbilt

It was a perception once (and in some cases still is) that 2.4 will prevent RF interference. Not so. Maybe your interference was always there but "masked" by PCM. i guess you are best off again starting with the basics. Check the plug cap is tight, R type plug, no metal to metal contacts, place Rx as far from the CDI as possible etc etc.
Good luck with it all, I know its VERY fustrating, I went through it some time back. Let us know what you come up with.

Some more specifics will help.  What receiver? Did you change any of the servos?  Switches?  Throttle linkage? I had a servo that was letting interference in to the system through it's electronics.  Changed the servo out and all my problems went away but that was on a 72mHZ sys.

I am running my AeroWorks Extra 260 50cc on a Spektrum DX7 with a Spektrum AR7000 receiver.  There are a number of things about my setup that others would say can cause interference but I've never had the first glitch from it.  This setup has been flying for over a year and a half and not a single thing.  I can't speak for the Futaba 2.4 stuff cause I don't own one but the Spektrum 2.4 is very robust.  Without knowing more about your setup we're just shooting in the dark.

I've seen 2.4 clear up RFI issues. Guy is using an Airtronics system though.

Well the Spektrum/JR 2.4GHz systems like most others are less susceptible to RF interference than a 35MHz system would be, but they are not anymore able to reject massive electrical interference than any other system. Usually..... If you get engine running glitches not present with the engine off with 2.4 systems, it tends to be spark related. That is things like a loose cap on the sparkplug, frayed shielding, wrong sparkplug like using a non-resistor type where a resistor type is required.

There are a few other documented cases of issues with 2.4 systems, but those tend to fall into the bad servo or extension category. I know you said nothing else has been changed, but I'd look for loose sparks first.

I had bad RF interference with my Spektrum AR7000 RX and the cause was the cap on the plug wire was not pushed down all the way on the plug. I'm using the 1/4 x 32 plug and the wire cap secures like a glow starter. Push down and twist to lock it down. Also someone told me a cracked plug will cause interference.

2.4 GHZ is not immune to RFI. However it is much easier for the ignition manufacturer to shield its product at that frequency. Any well made ignition system should cause not RFI on 2.4 GHZ. If you have interference when using 2.4GHZ, I would get rid of that ignition system. It is not well made.
I know someone will say I have this high priced, brand new system and it caused RFI on 2.4GHZ. My answer it is not well made despite its price

Hi all,</p>

Thanks for the input so far.</p>

I checked and the plug cap is tight and secure. The engine is an Evolution 35cc with the plug that came with the engine. I have no idea if this is the resistor type or not but would this not be the type supplied by the engine manufacture given the fact it is an engine made specifically for model use? How can I tell if it is a resistor type?</p>

Nothing else changed apart from the two batteries, still in the same location but of a larger capacity.</p>

The entire model was built by me from new items, engine, servos, etc and has only had a few flights while on 35MHz. No damage to any shielding, servo leads, servos, etc.

I am using a Spektrum AR7000 receiver, JR 12x Tx, upgraded switches, HiTec servos.</p>

I know I am missing something, but have no experiance with petrol engines.</p>

Please keep the suggestions comming.</p>

My 5 AR-7000's have been rock solid in performance, but that dos'nt make them immune to engine interference. My friend also uses the same receiver, and he had to send back his <u>new First Place engine</u> because of the interference that it was generating. They changed the ignition system, and when it came back, every thing was fine, no more interference.

Ed

The number on the plug will have the letter R in it somewhere.

How is your throttle linkage hooked up? metal to metal contact and vibration will cause interference. Most guys use golden rod or ny-rod for their throttle.

I had interference on my JR9303 2.4 module system.  It was so bad that the plane rolled inverted on its own one day.  Move the batteries away from each other.  Put the ign. batt on the firewall and the rx batt. near the rx..  Get  as much separation(12in is recommended) as possible for all the components.  I also made an RF shield for the ignition module out of a tin can.  Now I don't have any interference.  My plane had one of those no-name, plastic box, chinese ignitions that are famous for the RF noise. 

Hello, from reading all the postings, I was if anyone has experienced this problem.

I recently built a 1/4 scale Nieuport 11 powered with a magneto equipped G23 gas engine. I installed an AR7000 2.4 Receiver with Hitec 625 servos all around. The radio and servos all set up and operate perfectly when the engine is not running. Upon starting and running the engine, the right aileron proceeds to rapidly twitch. The right aileron is in the Flaperon slaved position. All other servos work flawlessly. I replaced the servo with another Hitec servo and servo wire extension but it still occurs. I replaced the wire jumper connecting to the receiver itself and the servo wire extension, but the jittering still occurred. The on board battery was always outputting at least 5 volts during these tests. It was also noted that “jiggling“ the servo wires plugging into the receiver does also causes the problem. I reinserted the plugs assuming a loose plug, but the problem continues and appears even worse. I figured it might be a mechanical problem with the plug in the rx unit itself, but why would it only occur when the engine is running?

Any thoughts?

Big Feet, try seperating your batteries and see what happens.

One guy at the field was getting glitches. Found out he took the ring off the bottom of the plug cap because it was hard to put on and off. Put back on and got a good ground everything was good. Another guy was getting glitches on a Quadra 35. Turned out he had a lawn mower plug in it. Gave him a Champion RCJ7Y and everything settled down. Another, when the shielding on the plug wire was grounded to the motor, the glitches would stop. The shielding was not attached to the plug cap.
Food for thought.

Gord.

Using a spektrum AR7000, I have a common Li Poly battery with separate regulators. One driving the receiver and the other driving the ignition. So far no glitches.

Is this wrong?

JD

I'm going to go a different direction here. Not meant to start an argument (and I'm just not up for one if it does). Take the following however you wish, use it or not, your call.

In my experience, when 2.4 is "glitching" it is nearly ALWAYS one of 3 problems:

1) Power
2) Power
3) Power

In the VERY rare instances it hasn't been one of the 3 above, then the problem has always turned out to be power.

=========

Check batteries..under known load. Check any regulators/wiring/etc...under known load. Check all connections under known load. Isolate every single piece of the power system that touches (directly or indirectly) the Rx, including the Rx itself. The known load should be at LEAST typical load in flight, preferably maximum expected load.

Check for connections/components that are intermittent while vibrating or suffering shock. Wiggle cables where they enter connectors. Tap/shock batteries, the Rx, all cables, all connectors. Run the system with the engine running but each component removed, and isolated from shock/vibration.

Replace batteries (even if they test "good" temporarily with other batteries, as a test.

Temporarily remove any components that aren't strictly necessary for testing. Unplug all servos but one, for example. Remove redundant Rx/batt/regulator/etc.

=========

In short...think of every single path/wire/connection voltage goes through ANYwhere in the system, and test/remove it.

I am having a heck of a time with an electronic ignition gas engine. I have the 2.4 Spectrum that will not work with this engine. I have one of the RVSC 26 engines from TroyBuilt models. The radio is rock solid as long as the engine is not running. I have read the 2.4 does not suffer from RF interference. I sent my radio to Horizon thinking it is a radio problem. They replaced the transmitter and receiver. I reinstalled the receiver and went to the field today. I charged up and did a range check. When I began flipping the motor, the servos all went hard over and were unresponsive. The LED in the receiver was flashing very fast. I cycled the flight pack battery switch off then on and the receive rebound to the transmitter. Again as I flipped the engine the radio went hard over. Thinking maybe the flight pack switch had failed, I connected the battery straight to the receiver. Same results. Next I tested my theory. I rebound the receiver with the ignition battery switch off. With the radio responding normally, I turned on the ignition switch and checked the radio. It worked fine. Then I pulled the prop through slowly and as soon as the magnet on the prop shaft passed under the ignition pickup sensor, the servos glitched! This happened every time I pulled the prop through. The receiver is well over 12 inches from the ignition module.
I am at a loss of what to do.

You now know how to make the problem repeat. You need not even rotate the prop through a whole rotation. Just flip the magnet back and forth under the ign. pickup. For a test, try putting a jumper wire from the sheath on the plug wire, to the crankcase and see if you still get the glitches and let us know the results. You've found out 2.4 isn't imune to rf noise, it just has more tolerance than 72.

This is weird, as I have the same engine as you. I had the engine in a Goldberg Ultimate. I had a throttle and choke servo right behind the firewall. The ignition was mounted right behind them, on top of the landing gear. The rest of the servos were right behind the ignition. Get this, I also ran ONE battery for the whole plane! I should have had problems, but I never. The only time the system glitched is when I replaced the sparkplug with a non resistor. I've read that the cap on the RC Excel style ignition could take a non resistor plug and shield it, but I've found that not to be true. I put a resistor plug back in and the glitching stopped. I would make sure your plug is a resistor and make sure the cap is on all the way. I'm not using Spectrum, I have an RDS8000, but they are both 2.4 radios.

Normally shielded systems don't use a resistor plug, but a if there is a fault in the shield system a resistor plug can stop the glitches. This is why motors without shielded systems like Quadra etc. only need the resistor plugs.

It is difficult to generate substantial radiation on 2.4 GHz, especially from a device that wasn't specifically designed to do so. Much more likely is that the R/C system is picking up the 5 KHz > radiation from the ignition system via the R/C system's wiring. Even a 2.4 GHz system can respond to extraneous signals in the audio voice range (and higher) sufficiently to foul the demodulation of the Tx's data.


Ed Cregger

Hi Guys,
I know a lot of time has passed since I first posted this problem, other projects took over.
Last week I made some more tests on the Evolution 35cc interference problem.
Test 1 Connected power directly into the Rx and Ingition unit. No difference.
test 2 moved the batteries, IGN battery temporially cables tied to the UC, and Rx battery as far rearward as possible. No difference.
Test 3 Tried another Rx, only connecting the thro and one elevator. No difference.
test 4 Tried a different plug (resistive type). No differnece.

The engine runs Ok for a very short time, up to 10 seconds, then stops suddenly. Not ceased, it stops firing and stops rotation normally. This happens from idle or even third throttle, running smooth until the sudden stop.
After all of this my guess is a faulty IGN unit, which is also causing the interference. Any other suggestions?
If this seems a fair diagonisis, which system is the best/easist retro fit. The Evolution system is $229, silly price.
The CH system and rcExl units are much cheeper and from what I've read on here, well respected units.

Any assistance appreciated,
Cheers,

Peter

Check with either CH Ignitions or RC Ignitions for a suitable RC exl ignition system as a replacement unit for your engine.

Karol