coloradoz

My Feedback: (38)

Hello all, I'm about to take the plunge into spark ignition motors - a friend claims that he used JR R600 RX and he was getting glitched - until he switched his system to Futaba. His general claim is that this solved his glitching problems.

Do any of you have similar experiences, are there really RX's out there that have problems with SI engines? or does the above fall into an isolated case incident or the urban legend catagory?

comments?

Aero330LX

My Feedback: (-1)

Hi,
Don't know about the R600, but I think if your freind switched brands because of Spark interference, he definately made a big (expensive) mistake. If he is bucking on the idea that brand makes a difference whether the rx. will get hit from RF noise from the IGN he is in for a big suprise! Actually he sold the better of the two radios at noise rejection, but that's really irrelavent...what is relevant is that there was a reason for the interference...Leaky plug caps, separation between components was not enough, conductive throttle pushrod, leaky plug wire, lost RF ring from plug cap, or some other problem that wasn't even caused by IGN. I've used JR recievers for over 18 years now, and not so much as a glitch from one of them. I fly gas and have never had an issue. In my gas planes I use only the best high end equipment available...10 channel topline recievers only in those planes. It's not just for the fact that I want my airplane to live longer, but I want everyone else around me to live longer too! I make them as safe as possible. When it comes to airborne radio equipment there is no expense spared on my airplanes. The higher end equipment generally has beter noise filtering, but that is just a backup safegaurd should anything go wrong in the air...I thoughly check ***everything*** on all my planes routinely. If there is a problem found even the smallest thing it is fixed or I find someone who can. Changing brands in your freinds case did not fix the underlying problem of his Interference...all it did was mask it. You dont get do overs with interference, but it will rekit one in a heartbeat. JR has patented noise filtering in their recievers, if your freind was getting hits, there was something wayyyyy wrong in the airplane, or it was some sort of rogue outside interference.

FLYBOY

My Feedback: (11)

I never had an issue with my Gere sport running PPM but I did with my PT-19 running PCM. I had the kill swith too close to the on off switch and the radio kept going into fail safe. Drove me nuts. I moved the kill switch as far forward as I could and it solved the problem. Make sure your throttle pushrod is not metal, or if it is, make sure it is far enough forward of any other radio gear. Any receiver you run should be fine. Its more of where you put it than what you put in. Keep the radio gear back away from the engine components and you won't have a problem.

coloradoz

My Feedback: (38)

Thanks for the data points and tips. Anything else I should look out for?

Geistware

My Feedback: (16)

JR receivers are mostly single conversion while futaba is dual. Both are good at rejecting noise if you have the ignition system properly grounded.

JWN

My Feedback: (42)

JR's single conversion receivers are very good at rejecting interference due to the way they implement single conversion. They call it ABC&W. They used to have a pamphlet that explained how this worked and why it was better than many of the other manufacturers implementation of double conversion.

Pretty much any RX will be suitable for a spark ignition engine if you follow some very basic rules for separation. Use a nyrod for the throttle control. Do not place the ignition module or battery, if one is used, near any of the other radio equipment. The same goes for any ignition related wiring or switches. Spark ignition has been around since before the days of even FM R/C units and many modelers were successful. If that were true 30 years ago, it's going to be more true today.

John

coloradoz

My Feedback: (38)

Thanks John, I'm wondering if it makes sense to put in any passive arrest for any stray RFI - I remember, way back when, we used to wrap the RX antenna around a ferrite bead. Do any of those tricks improve the situation?

...ajs

Roquewj

My Feedback: (4)

Coloradoz,

I had a similar problem with a JR R600 receiver.
It happened after many years of good performance. I had a R600 RX installed in two different planes, with different engines ( a G-38 and a Q40).

Please take a look on the post http://www.rcuniverse.com/showthread...031&forumid=27

It might help you to decide.
I still use JR receivers in all my 14 planes, without any problem.

Hope it will help..

Forgues Research

My Feedback: (7)

Way back maybe on the ferrite beads, but things have changed.

Read this

Ladyflyer

My Feedback: (2)

JR did a good job on selling the after-the-fact filtering they added to the ceap SC receiver scheme. Unfortunately in the real world there have been some problems.
As far as ignition noise the best plan is to eliminate it at the sources. Good single point gounding ,shielding and bypassing (with caps) all possible sources of pulse generated noise are the way to go. Relying on a cheap filter scheme to take it out after the fact is risky at best.

Keep all the ignition leads as short as possible .A shielded sparkplug and plug wire with a 5K ohm resistor in series helps keep the radiation level low. The power to the ignition system should be close to the ignition system and bypass caps used at the termination points .Eliminate metal to metal joints as well .

DavidO

LF,
I'm interested to learn exactly what you mean by your previous statements :-

1) "after-the-fact filtering they added"

2) "to the ceap SC receiver scheme"

3) "Relying on a cheap filter scheme to take it out after the
fact is risky at best".

Could you be more specific in your explanation please ?
DavidO

Aero330LX

My Feedback: (-1)

on #1 she may be talking about Anti-Blocking and Cross Modulation (ABC&W), but nobody knows any of the particulars of it... I know because I have asked before, and was told by Horizon that that is proprietary information that only R&D has any knowledge of. It's patented.

On #2 couldn't tell you what that means...don't think ceap is a word. LOL

On #3 Same deal as number 1... hogwash! When you fly fly 3-5 times a week 6-9 flights a day for 17 years and never have so much as a glitch I wouldn't call that cheap. I have, and I know this, I wouldn't trust a Futaba reciever with a range more that I could spit. I have dual-conversion 940's on a gasser giving me an range of 100 yards engine off, and engine running only a 1% reduction. I have a single conversion 950 on a glow plane giving me a range of 200 yards...I had to walk out in the tall grass to find the edge of the range! LOL Futaba guys in my club? They have told me themself that those expensive synth recievers aren't even close to that...at three times the price. One often wonders where some of the stuff comes from that some people post.

DavidO

Aero330LX,
Thanks for your interpretation on LF's comments.

With respect, I shall wait for LF's response before responding positively and constructively to a couple of your points.
DavidO