I had my Spektrum DM-9 upgrade for my 10x for about a week, and had 4 flights on it with no issues. Then the next time I wanted to fly the transmitter module was totally dead. The transmitter worked just fine with a 72mhz TX module in place, though.

Voltage on the Digital readout on the 10x is a solid 10.7 volts, while with the DM9 it varied constantly between 10.7 and 10.2 volts. No module in the Tx also showed 10.7 volts. This leads me to believe that something shorted inside the DM9, causing the voltage down spike every time the transmitter energized the RF section of the DM9, but due to the high current draw, the trusty 10X shut off power to the DM-9 whenever it engaged.

Sooo. . I sent the module, and antenna, off to Horizon for repair. Today I got it back. In the package was the repair slip with a little note.

Now THIS is condescending, IMHO (. .Like. . hey stupid, use the right voltage. . . )

"Replaced module and antenna in the spirit of customer service. Is a non-stock battery being used? as that may greatly shorten the modules lifespan. .?. . "

"In the SPIRIT of customer service". . . how grand. .how nice. . . patooie!!!!!

So, I call Horizon to see what the rated voltage range for the DM9 is. We all know it's not just ONE voltage .. it has a range. . probably 9-12vdc, because that is the range of the 8-cell battery packs used in our transmitters. Sounds logical, right? After explaining the situation to the "tech" (I use that term loosely), I asked what the rated voltage range was for the DM-9 transmitter module. He puts me on hold (he had to actually CHECK on this. . .) then comes back with the Horizon Service pat answer. . "9.6 volts".

Ya know what. . When my TX gets to 9.6 volts, I start looking around for a charger. . so I ask him. . You sure there is no "range" of voltages, like from 9 to 12vdc? He insists. . 9.6 volts. . ONLY 9.6 volts. So I ask. . well, isn't this module compatible with a 10X, 9303, 8103 and all other JR radios? And he says. . yes, it is. So I ask. . well. . .How am I supposed to regulate the voltage in my 10X to only 9.6 volts, if the wall wart charger supplied by JR and Horizon Hobby, with THEIR radio, charges the stock pack in the radio to 11.3 volts?

About right then he hung up on me, so I never got a definitive answer to this very important question.

So. .I'm gonna throw this out for general thought, conversation, and consumptioin. .

What IS the acceptable voltage supply range for the Spektrum transmitter modules? Don't be coy. . let's get a firm and definitive answer for this one .. I REALLY need to know, so I can call Horizon back in a few days, complain to their Head of Technical repairs about the techs conduct, and then inform HIM what the correct answer should be.

Since the crew here at FG seems to have it ALL together on things like this, let's figure it out, and then improve things for the rest of the RC world by getting the correct answer to the Techs, so that THEY will be able to do their jobs better in the future. As for myself. . I'm really disappointed. . I thought the guys up in Champaign, Ill. had their act together.

Did you ever get an answer from HH?