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-   -   JR rx, heard bad things (https://www.rcuniverse.com/forum/rc-radios-transmitters-receivers-servos-gyros-157/804045-jr-rx-heard-bad-things.html)

pepper-RCU 05-26-2003 10:45 AM

JR rx, heard bad things
i was going to change all of my radio gear to JR but someone told me that they have had a bad problem with their pcm rx systems. also something about the tx also haveing the same problem. does anybody know about this. i am not trying to bad mouth the company or anything, just hope it's a simple question, i really like JR stuff and will more than likely go with them anyway.


pcm 05-26-2003 01:02 PM

JR rx, heard bad things
Sounds like you were misinformed by the "other brand" pilot. I have Been flying JR PCM for...Gezusss I am older then I thought.

Anyway you wont go wrong with your choice. ;)

pepper-RCU 05-26-2003 01:12 PM

JR rx, heard bad things
cool, i sure was hopeing it was some bad info!!


jrplane 05-26-2003 01:45 PM

I have been flying JR PCM for quite some time and have never had a problem.

Homebrewer 05-26-2003 01:45 PM

JR rx, heard bad things
Been using JR for 7 years with no problem. However, I do prefer using Hitec flightpacks which are much cheaper and as good, if not better, than JR.

MO_Radio_Tech 05-26-2003 02:34 PM

JR rx, heard bad things
Every once in a while someone gets on here an slanders JR. JR PCM is reliable.

JohnVH 05-26-2003 03:12 PM

JR rx, heard bad things
I only fly JR now. No problems with the radio ever.

bentgear 05-26-2003 03:36 PM

JR rx, heard bad things
"JR can't be any good, twice I have had planes go in when someone turned on another radio."

Oops, I guess that would have happened no matter what radio I was using. One was PPM and the other PCM. Contrary to some peoples thoughts, all the major brands are some pretty good radios. I think you should choose a radio based on how it feels in your hands, does it have the features you need, can you program it, and will it match up what you are already flying.

BTW, I fly JR and love them.
Ed M.

JWN 05-26-2003 07:44 PM

JR rx, heard bad things
I sold all of my brand F radio equipment about 14 years ago in favor of JR and have never looked back. I have only had one radio related crash and that was because I did something stupid which resulted in the power lead from the switch being cut.

I hear the stories from various people saying JR this and JR that. Then again, I also hear the same stories for all other brands yet they never seem to happen when I'm at the field.

JR makes extremely good equipment and I wouldn't continue to install it in my models if I thought it was anything else.


visioneer_one 05-26-2003 09:35 PM

JR rx, heard bad things
I just had my second radio-related crash - it appears that the aileron circuit in one particular RX quit working. I can't blame the crash 100% on the radio, as I'd have caught it if I'd done a proper ground check before taking off.

I'm going to continue using JR gear though. Two oddball failures over a ten-year stretch == a pretty good track record.

Aero330LX 05-27-2003 12:59 AM

JR rx, heard bad things
I've been using JR gear now for 17 out of 18 years in the hobby. Radio related failures = 0 (zero). This may be hard to believe, but I haven't even had a glitch from one. I can't imagine why someone would state that JR PCM recievers are faulty. Me thinks what is faulty here was the information that somebody gave you. :D Not to worry man, those recievers are solid as a rock. I bet I have 20 recievers here...everything from old wide band stuff from the mid and late 80's, to 7 channel "Z" system rx.'s, to the latest 10 channel 940's, and the 955.

MO_Radio_Tech 05-27-2003 03:43 AM

Hey, send that receiver into Horizon. They wll give it a good go-over and figure out what happened.

visioneer_one 05-27-2003 04:16 AM

Re: vision---one

Originally posted by MO_Radio_Tech
Hey, send that receiver into Horizon. They wll give it a good go-over and figure out what happened.
You bet.

Off-topic re: your tagline. For some reason the melody from "Raindrops Keep Fallin' On My Head" runs through my head every time I read it :D

MO_Radio_Tech 05-27-2003 04:42 AM

JR rx, heard bad things
Well I certainly hope no weedeaters or aircraft fall the from the sky like "raindrops falling on your head"!!! Would need a good umbrella.

By the way, what receiver, servo, extensions, etc were involved in this? There are all knds of things that can happen.

Here is and extrmely rare scenario. A servo motor can die (defective, or caused by fatigue from flutter in surface, etc.), lockup, and result in a blown servo amp. Blown servo amp can be a short, sending 5V to the signal pin and damaging the decoder IC of the receiver. I have seen this happen several times.

Bottom line, sometimes some goofy problem in a dying servo can kill one channel in a receiver.

Could also be something as silly as one cracked solder joint.

visioneer_one 05-27-2003 01:46 PM

JR rx, heard bad things
The receiver is a JR R226. Servos are FMA 3501 on ailerons and elevator, a 3501M on the rudder, and a Hitec 422 on throttle. 700 mAh rx pack. I also had a Gem 2000 battery monitor installed. There was a standard 9" long extension connecting the single aileron servo to the rx.

After recovering the wreckage I plugged th aileron servo directly into the rx aileron channel. No response. I then plugged it into the throttle channel - and it worked. It alo worked when plugged into the elevator channel.

You may be on to something there regarding a dying servo. I've had problems with the motor wires fatiguing and breaking loose from their solder joints - both the elevator and rudder servos previously failed in the same way. No damage to the plane in either case - I guess I was lucky.

(the elevator servo failure was particularly weird - the servo died at some point after I landed. I pulled full up elevator to drop the tail, then killed th engine and walked out to retrieve the plane. WHen I go to it I noticed that the elevator was still deflected up, and no-one was holding the radio... The servo was completely non-responsive. It wasn't 'locked' in place - it behaved as though there was no power to it.)

In both cases I removed the offending servo, resoldered the wires, and added a blob of electronic-safe RTV to keep the PCB and wires from jiggling about. I *think* I pulled the aileron servo and potted its wires at the same time that I repaired the elevator servo, but I'm not 100% sure.

I'm going to test the rest of the radio gear later tonight.

MO_Radio_Tech 05-28-2003 03:39 AM

JR rx, heard bad things
When you solder the wires in a servo, also glue them down with Contact Cement. This prevents wires from coming loose from vibration fatigue.

If you open most servos, you will see this yellowish rubbery glue. If you sent the servos in for repair, techs would add more glue for this very reason.

You could be on to something here, hope you can track this Gremlin down.

If the receiver was bad from the factory, the Aileron channel would have probably been dead from day one, due to static damaged IC or cracked resistor/trace on aileron.

Jesse-RCU 06-03-2003 03:15 AM

JR rx, heard bad things
there is good and bad in all of them. i have been flying with Jr ford 8 years now never had a problem, not saying that i wont, but it has been a good one, knock on wood. and plus it is very comfortable to use.

good luck with your choice

geneh-RCU 06-03-2003 09:09 AM

JR rx, heard bad things
I have been flying JR PCM for a long time! No Problems........

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