george2005

Danny Snyder,

I have a Radio Shack # 23-449 AA 1,000 mAh NiCD 4-pack that I wish to use in the Spektrum DX6i transmitter using the same charger(s) that I use to charge my 4-pack NiCd receiver batteries. Do I need to modify anything inside the DX6i transmitter.

I attached a JR transmitter charge lead/pigtail (not attached to any charger) to double-check for negative voltage on the transmitter center post of the charge jack, and to confirm that voltage is "continuous" from the batteries to the jack. I get no voltage reading, neither plus nor minus. Therefore the above question.

dsnyder

You do not need to modify anything to charge through the system, the plug is center pin negative.

george2005

Danny Snyder,

I understand that the charging should be the same as my JR Galaxy Computer 8 PCM, JR XP8103, etc., all of which charge their 8-pack NiCDs just fine. However the DX6i apparently has some component (such as a diode possibly?) that does not allow the 4-cell side of the high-end charger MEN C-50/4 charger to sense conditions properly and charge the installed 4 cells while protecting the batteries and the radio from heat and/or consequential damage.

As mentioned in my original post, I was testing with the understanding that the center charge post is negative, as in my other radios.

The Radio Shack NiCd batteries mentioned above do charge properly outside the transmitter either in a 4-pack battery holder or in all my JR radios.

I suppose that my next question should be "Can you provide me with a circuit diagram?" or tell me what component I need to look for, and where, etc. There has to be something there that has not been addressed. I do recall that in the early 1980s there was some component in at least one of the Circus Circus JR radios that was a problem we helicopter flyers figured it out and corrected.

I do thank you for your efforts to help, not just me but all of us with all our questions and needs.

george2005

Danny Snyder,

Being a graduate engineer and with a ham radio ticket I can't leave such things alone. So further update to you is in order.

I have 2 DX6i transmitters. I pursued my effort to charge through the transmitter charge jack of each starting with the JR wall wart.

As I said, I tried charging both of my DX6i transmitters using the JR wall wart charger first, then an MRC Super Brain, and a Duratrax Charger and each (except the wall wart, of course) gives me an error message on each of the tranmitters. I tried NiMHs and NiCds and everything does just fine outside the transmitters.

Other DX6i owners have had the same experience as I. So my previous question/request does still stand.

Again, thank you, Danny.

george2005

Danny Snyder,

Sorry, I did forget to specifically mention that I used an adapter for the JR wall wart 4.8 volt pigtail to the standard JR transmitter plug for the DX6i charge jack. I am not, and have not, tried to charge the 4 cells using an 8-cell voltage, just so that you know - - -

bmitchell138

George2005,

Did you find out if there is a circuit protection diode that keeps a field charger from sensing the Tx battery voltage? I would like to get rid of the wall wart charger and use my field charger but I have run into the same problem as you.

george2005

I did not get a correct answer from anyone, including Horizon's staff, engineers, etc....

Two things as follows:
1) Using a JR brand wallwart and other chargers currently on the market today always heated up the NiCd or NiMH batteries I use in the DX6i, not super hot, but any heat damages batteries and electronics over some period of time.

2) I looked over the circuit and determined for myself that no damage would occur if I soldered jumpers from the plus and minus wire connections either at the circuit board or at the charge jack to the respective plus and minus connections on the metal clips of the plus and minus sides of the 4.8 vdc NiCD or NiMH battery assembly in the transmitter.


I can now charge the 4.8 vdc NiCD or NiMH assembly in just a few minutes using one of my MEN C-50/4 charger available in the 1970s and 1980s, which was really my goal when I first asked the questions about the circuitry, diodes, and such.

The charger that I just mentioned charges at an extreme rate but the batteries do not heat up at all at any time during the high-rate charging. It is a shame that the MEN chargers are no longer on the market, or that the circuitry is not available to us this day in age. Reverse progress I suppose - - -

Also, I can charge the batteries now using any other NiCD/NiMH charger (I also use peak chargers at the field every once in a while) using the car battery as the power source (well, my car also has 110 VAC so I can also use a MEN charger if I so choose).

The only comment I might make is you may want to wait till the warrantee has run out. I personally was not concerned over a warrantee issue as I have a JR 12X, a JR XP9303 and a JR 8103 all of which I also use on 2.4 GHz and those JR radios never presented an issue relating to charging with my MEN chargers or peak chargers. I just like the DX6i because it is so light (made in China?). I did get one of the defective DX6i transmitters when I bought a Blade 400 3D, but as soon as I removed the transmitter from the box it was quite obvious on that transmitter that the right stick assembly was really defective (crunch, crunch very obvious) so I returned it to the LHS the next morning and they replaced the entire package.

Having mentioned the defective gimbal issue, I trust you are aware of the www.HorizonHobby.com bulletin out on the many defective DX6i gimbals. Before we figured out the problem here, we lost 10 or more airplanes at our field, and some newcomers quit the hobby due to this defect costing them so much when they were just getting started. If you have not received notification or otherwise have not become aware of the defective gimbals, look at Horizon's support webpage for the DX6i transmitter.

If you are not quite sure I provided adequate explanation of how I ran jumpers directly from the charge jack to the battery clips, please make me aware of it and I will try to find photos that I probably took at the time I make the mod. I normally do document mods that I make.

However, I am going to be out of pocket for a few of days and it may take a while for me to go through the thousands of photos I have (when we are in Europe we take about 2,000 to 5,000 (or more) photos a week so I have lot to sift through if need be).