JR radio internal battery

On 28 Dec 2006 19:37:44 -0800, I said, "Pick a card, any card" and "ahdofu" instead replied:
Those batteries typically have a shelf life and useable life of around 10 years. Ordinarily, that's more than enough time to get 100% use from it before you replace your equipment. Any other kind of holder would not be reliable enough for backup memory. Standard practice was to use a soldered connection for reliability. Today, they use non-volatile RAM for storing things like programs and such. Real time clocks still use a lithium battery which may or may not be soldered in place. -- Ray

I'm guessing that the repairs will cost around $50. This amount brings into question whether it is worth repairing the radio. Unfortunately my radio works just fine (at least it used to) and I just find it a waste to toss a perfectly OK radio. My old sport watch never failed in use and yet I could unscrew the battery cover and swap the battery with a new one. For JR perhaps cost was a factor or perhaps it was the reliability issue that you've mentioned but to me this is subpar engineering. Thanks for your comments though.
Ray Haddad wrote:

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What really ticks me off is that when the memory battery dies, or is disconnected, the radio's computer drops its operating system. Not only do you have to return it to get the battery replaced, but they also have to reload the operating system. Even if one had a proper battery holder, removing it without offering the system back up voltage in the interim would lead to an R/C transmitter that doesn't know if it is a scanner/TV set/microwave oven, etc.
Are you sure that the newer JR rigs use non volatile RAM? I wouldn't assume so without some form of verification. Icom amateur radios did the same thing for a while. We hams raised cane on them for this dufus form of engineering. Happy New Year.
Ed Cregger

are you sure it holds the operating system? I would have thought that would be in an EPROM of some description, as backing up a few bytes of user changeable data is one thing,storing the OS that does not change is something else

See how ridiculous the idea sounds? Yep, my JR X-347 drops the operating system if you break battery continuity.
I don't know if my JR 8103 and 9303 are the same way. I hope not.
Ed Cregger

well I am no electronics designer but I would not have done it that way ,there must be a logical reason like the price of Eproms over volatile ram or something similar

Mine is an X388S which, I think, came after the X347. Following the battery failure the radio was still functional except that all of my programming had been erased. Now if the radio loses its functionality all toghether then that is really a poor/cheap (I have more colorful words) design. I grew curious following your question and checked the XP9303 manual. There it says that all programming data is stored in flash memory. It also appears that there is no internal battery to replace either. If this is the case then it is good that JR has learned from its design flaws.
Happy new year to all, Matt
Ed Cregger wrote:

Perhaps it was simple stupidity. "Brand F" has been using flash for over a decade...

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You know, now I remember that the 388 didn't use that battery to hold the main OS of the radio. Thanks for jumping in there. I think the X-347 was the last of those rigs.
I can live if just the channel memories are lost, although, these days, there isn't any excuse for that either. Who knows, maybe today's radios do not lose the channel memories.
Nevermind....!
Ed Cregger

I had a "discussion" with JR and later with R.Stephens about the backup battery in early JR radios.
Was told but the JR tech that only they had the skill and technical know how to change the battery.
Complained to the highest up and was told much the same, I said BS, then he admitted that it was possible and that the processor had to be restarted with a jumper to reload the default values. That the system was programmed to lock up if there was a RAM error.
I asked what pin to what pin to jumper, was then told that the information was secret and proprietary.
Send it in and pay your money boy we are the all powerful
Hugh 50+ years of designing, prototyping, repairing RC systems.

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I'll have you know that I have this simple stupidity thing down pat!
Another poster said that the X-347 was the last JR to use the system that I mentioned previously. The next radio, the 388 and on up, did not use the memory battery to hold the OS. It all came back to me when he mentioned the 388.
Ed Cregger

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So the OS was present on ROM, but you had to know how to initiate it. That would make more sense.
Ed Cregger

Sounds like one would get a 3v (or whatever is used) source with a couple of leads - and solder (or clip if possible) them to the board in parallel with the JR battery to keeps things going while you remove the old one and solder in the new one.
Doesn't seem too hard, but I haven't tried it
David
Hugh Prescott wrote:

"quietguy" wrote in message news: snipped-for-privacy@REMOVE-TO-REPLYconfidential-counselling.com... Yep, that's how it is done, unless you are forgetful like me and don't get around to it in time. Now I have a JR X-347 in like brand new condition that doesn't know it is a radio. Should I spend the money to bring it up to date? I have an 8103, a brand new still in the box 9303, a DX-6 and a DX-7 Spektrum radios. Oh, what shall I do?
My legs are bad from diabetes, so my ability to walk is very limited. Believe it or not, this is why I bought the Spektrum radios - so I wouldn't have to walk to the frequency control board and back again after finishing flying for the day. No other reasons. Well, maybe some curiosity.
Anyone want to buy a brand new, never flown 9303 on six meter PCM with four standard servos? I'll let it go for $450 plus shipping (48 US contiguous states only). IIRC, this saves the buy $200. It should be on 50 MHz channel 04. New the end of last summer. Never removed from the box. No, I won't go lower in price. US Postal money order only.
Ed Cregger

Would I have to brush up on my code? mk (-.-.--.-)

Not anymore:

Hi
As the "proud" owner of 2 JR radios - an X-347 and an X-388, the 347 at least being well over ten years old (nearer fifteen I think) but still working well, this thread has rather spoilt my Christmas as it seem that both sets are well overdue for self-destructing!!!!
However, having had too much homebrew last night and having blurred vision and shaky hands as a result, this morning seemed the obvious time to delve into the innards of my X-347. So having taken the back off, undone every screw in sight, unplugged every connector I could find, turned it upside down and shaken it, I was left with a workbench of assorted bits and the odd screw and spring bouncing round the floor - strewth, that's were the cunning devils hid the backup battery is it, I have often wondered. Having stirred the pile of bits with my finger and poked them a few times with a screwdriver I finally realized, "Taking that apart perhaps wasn't a very sensible idea!!".
Having just re-assembled it without too many bits left over - just one screw actually (said proudly) - and finally figuring out where the 6 little springs went, I took a deep breath and turned it on. There was immediately a continuous warning buzz and a "backup error" message on the screen. However, after a couple of seconds, the warning buzz stopped and the display reverted to normal. It now appears that all my personal model settings have been lost and the Tx has reverted to its original factory settings, otherwise all seems fine.
Is this an indication that perhaps not all X-347 sets are the same and if I were to replace the backup battery, I would not lose the programming - or isn't life that simple??
One thing I would point out is that I live in the UK so mine is a British radio - so could it be that UK sets are different and do not lose the programming?
Regards
KGB

Could be...........does it drip oil?
Abel

Hi
Actually, it very nearly does just that.
A few years ago, I played around with diesel powered models. Since then, the silver finish on the front of the X-347 has gone all soft and wrinkly (a bit like myself!!!).
I am not certain of the reason, but my best bet is that the ether content of the diesel fuel acted as a solvent for the paint or whatever the silver finish is. Certainly it got well covered in diesel fuel. My other JR Tx (X-388) has only ever been used for glow models and the silver finish is still fine.
I cannot figure out why some flyers at the field always have immaculate trannies and mine usually look as though they have just been dragged from the trash can, usually ending a day's flying covered in oil and liberally dripping model fuel - and yes I do clean them when I get home. 8^)
Regards
KGB