JR 9XII or Futaba 9C Super?

Although I prefer Futaba, I had a run of bad luck with their 127DF receivers a few years back. Switched to Hitec receivers and never had another problem. The 'entry level' 127DF, I agree, is NOT very reliable.

the only thing that puts me off any of these 2.4ghz systems is being tied to their brand of RX, and I dont think we will see sub $20 RX's for any of them

If a transmitter is converted to 2.4Ghz with a module (from any supplier), what is the downside relative to buying a dedicated system that will only operate on 2.4Ghz? Both my Hitec Eclipse and my Futaba 9C accept modules. Is there something I should know before buying a 2.4Ghz module for either?

Harlan

Harlan, My feelings exactly. A dedicated 2.4Ghz radio is just that. BUT, I can buy an XPS module/receiver combo for $189 and I have 2.4Ghz. If I want to go back to 72Mhz, I just put the 72 module back in the transmitter and use a regular receiver. Best of both worlds. The XPS is available for a bunch of different brands of radios.

if you convert a Futaba set with the Spektrum module you loose some of the unique Spektrum features, but apart from the aerial in the wrong place it should be more or less the same as a new 2.4ghz set,and it saves reprogramming the new set, and the 9C 2.4 is not out yet (not sure if its planned)

Yes, Jim, it seems to me that a guy who has "invested" significant bucks in decent radio equipment, including transmitters, receivers, single channel modules, synth modules and whatever else would be wise to stay with the equipment he has and simply add the 2.4Ghz module and receiver for additional planes. I would hate like heck to buy new receivers for all my planes when I can still play them on channel 44, for instance, or nay other channel I've been using with the synth module. I would think it would make good economic sense.

Harlan

As far as I understand from my googling, there can be a difference in the delay between stick input and servo response. Whether or not this actually makes a practical difference, I don't know.

In a conventional radio, the computer produces a pulse train (each channel is one pulse, and they have to be separated by a certain amount of time) that it sends to the RF module. If you swap the RF module for a 2.4 one, the new module has to wait for that slow pulse train before it sends data off in digital packets.

In a native 2.4 system, the computer does not have to create the slow pulse train at all. It can simply send a fast data stream to the RF module. This allows for faster response between stick and servo.

The question, of course, is if the manufacturers make use of this potential advantage. Spektrum claim to do so, but nobody knows if JR's DSX9 will simply be a 9X with a 2.4 module glued in the back. Since their marketing does not mention anything about improved speed and response, that's probably exactly what they have done.

And if that is the case, then the only advantage is, as Kevin says, that you get the antenna in the right place. Having it stick out the back of the transmitter cannot possibly be practical.

I don't know how heavy the 2.4 is, but length makes a big difference on the balance.

XPS actually sell a product that solves the problem:

Thanks. I have browsed a little on their pages now, but I cannot find any information about anything that deals with the world outside USA. No dealers and no information about where in the world their products are legal to use. They seem to only care about the American market.

The lifetime warranty is confidence inspiring, but when they decide to copyright the use of blue circuit boards and blinking LEDs, they have obviously lost grip on reality.

I need a new radio anyway, but I am still considering the option to get a synthesized conventional radio, and then possibly add 2.4 later if I want to. In that case, XPS gives me an alternative (provided they are legal here) to the factory system, which is nice to know.

These guys do it right! They have taken all of the downsides in question into consideration when developing their products. They rock!

I'm sure Jim will take care of it.

I've owned both and still do, and they both are very good sets for the money. The main reason I've swopped to the JR set are as follows.

Both are easy to program once you get used to how they do it.

Jr has 7 point pitch and throttle curves. Futaba only 5. The ability to have seperate trims on Throttle Hold on JR. (Futaba defaults to "Normal Curve" settings when in Throttle hold.

Things I miss from the Futaba Throttle Governors were a doddle to set up especially the GV1. It was possible to set the tranny up so 40% = 1400rpm, 50% = 1500, 60% = 1600,

The timers were more flexible on Futaba. ie. it could start the timer above a certain throttle position.

There were other things but I cant remember them right now.

I think it's going to be the way to go which is why I've switched. I got my X9303 a week or so before Christmas. Nice radio and the resolution made for some interesting test hops. Subtrim resolution is double that of both my 9C and my DX7. Programming is very straightforward for anyone with a bit of computer Tx time under their belt and the scroll gizmo is very fast so dialing up values takes no time at all.

I've heard Euro power levels will be less than those here in the States as well. I received my X9303 a few days before Christmas and go a couple helis set up on it already. Nice radio, pretty easy to program, but it's got a few TINY issues that JR could have addressed better, but nothing show stopping. (Mainly the fact that you can't use the GYRO SENS features with a 6ch Rx as the Tx only recognizes AUX2 for the gain control and not GEAR *and* AUX2 like the DX7 does - easy enough to work around by using end points to set the gain)

Yes, the balance, like the DX7, sucks. It's "Bottom Heavy" and when using a neckstrap, I find myself having to hold the radio "flat" when I fly. G-force makes a bracket you can buy to move the strap attachment point below the power switch to get the balance point correct again, but a couple Helifreak.com users (Fireup and machinegun) make them too. I like fireup's because it doesn't interfere with the power switch.

I was going to go that way with my 9C, but had the same concerns. My

There is very little difference between the two makes. Both have there good and bad points and both sets of manuals leave something to be desired.

The only downside of the JR radio is the lack of a timer operated by the throttle stick, but most people would not use that anyway.

I have the opportunity to fly both regularly and have no preference.

| Take a look at the Extreme Power Systmes 2.4Ghz modules/receivers combos. If | you love your existing radio, you can upgrade it to 2.4Ghz with their | products. IMHO, they are hands down way better quality than what is put out | by JR, Futaba, etc.

Why do you say their quality is better?

| If a transmitter is converted to 2.4Ghz with a module (from any supplier), | what is the downside relative to buying a dedicated system that will only | operate on 2.4Ghz?

The DX7 and X9303 have a `model match' feature that lets you tie a RX to a specific model number in your TX (perhaps I have the specifics on how they do it wrong, but the end result is correct) so that your plane won't turn on unless you've chosen the correct model number on the transmitter. The circuitry isn't there to let you do this with an add-on module.

The 2.4 GHz stuff could be more carefully integrated than this in the future (for example, two way communication, having some telemetry display on your TX display), but for now I think that's the only thing missing.

| The question, of course, is if the manufacturers make use of this | potential advantage. Spektrum claim to do so, but nobody knows if JR's | DSX9 will simply be a 9X with a 2.4 module glued in the back. Since | their marketing does not mention anything about improved speed and | response, that's probably exactly what they have done.

The X9303 has the same `digital data path' internally as the DX7 so it should have the same low latency (and no, I doubt I could tell the difference) and it supports ModelMatch and such, so I'd expect any new radios to from JR to work the same way.

| The only downside of the JR radio is the lack of a timer operated by the | throttle stick, but most people would not use that anyway.

It's more commonly used than you might think. For example, it's useful on an electric glider to have an idea of how much battery you've used (and therefore how much you have left.) Or comparing it to your flight timer gives you an idea of how good you've been at finding lift, as opposed to cheating and using the motor.

Or if it's a standard helicopter/plane, it tells you how long you've actually been flying, as opposed to fiddling around on the ground. You could get around this by just tying the second timer to a button that you hit when you start flying, of course.

(I don't know anything about the 9XII having or not having this capability, I'm just saying that it's not that uncommonly to use it.)