I plan on buying the 2.4 plug in modules for my JR9303 and Hitec Eclipse 7 only when I have to.

Anyone have any thoughts on quality differences between a 72Mhz Tx with a 2.4 module plugged in vs a 2.4 Tx?

channel 22 is ready for service !

Teachu2, it wasn't I who said the 72MHz stuff was junk. It's the folks both here and at the flying fields around the country who are saying that if you aren't flying 2.4 stuff, you are a cheap skate and should not be in the hobby because the 72 MHz stuff is junk. They are the elitists. Their attitude is if you don't have the very newest technology, you shouldn't be flying. You'll see that attitude right here in this forum a lot. I still love the 72 stuff and will continue to use it, although I also have 2.4 stuff. And even if they auction off the 72 MHz frequencies, which I am confident they will, I live in Arkansas. I doubt thay anyone at my flying field will pee in their pants for fear that an FCC cop is going to come along and catch us flying 72 MHz stuff. The feds here are still chasing the guys making white lightnin' out in the woods.

I'm with you all the way, jollypopper. My sentiments exactly and I live in Jacksonville FL.

[sm=thumbs_up.gif][sm=thumbs_up.gif][sm=thumbs_up.gif]
Let the elitists enjoy their new shinning toys, that doesn't bother me a bit.
Regardless of the name somebody may want to call me, I fly in a budget, but I fly the best I can, and I enjoy it much.
Life is not to have the best of everything, but to make the best out of what you have.

I had to get a 2.4 set up to fly at the few Fly-ins I attend. But I just do not trust it yet. I have put it into a 2 meter sailplane to see how well it behaves before I put it into anything else. I never had any problems with my Ch. 52, 18 or 59. We shall see......

Does anybody know the reason for the drastic change of frequency from 72 MHz to 2,400 MHz?

I mean, couldn't the technology of auto-binding be applied to the lower frequency of 72 MHz?

Like Isaid above, there were several things that went into the decision. First off they needed to go to a frequency range that didn't require licensing to operate in. The 3 easiest areas that would fit that bill would be 900 Mhz, 2.4 Ghz, and 5.8 Ghz. Next would be to look at the equipment already operating in that frequency range. Right now in the 2.4 Ghz range there are a lot of existing computer equipment already operating on 2.4 Spread Sprectrum.But here all of this equipment is designed to not interfere with each other. In areas such as 5.8 Ghz there is a lot of equipment already operating, but those don't get along with each other and could interfere with each other. Next would the the antenna size. Basically, the higher the frequency the shorter the antenna would be. If they dropped to a frequency lower than 72 Mhz they would have an antenna longer than the 39"used by 72 Mhz.

There are just some of the reasons why 2.4 Ghz was choosen, there were probably many many more.

Ken

Remarkable explanation, Ken.

That was something that I have been wondering for a while.

Thanks

If you type "900 mhz" into a google search, you can also get an idea of the sutff that doesnt play well together in that freq range. Like cordless phones, baby monitors, etc.
I think 900 mhz could have been better than 2.4 from a signal penitration standpoint thou. And 5.8 ghz I think is much worse than 2.4 in that regard.
Think about the issues weve seen with 2.4 signals not getting through some aircraft fuses and how much more critical antenna placement is vs. the 72mhz stuff. Seems to me that 5.8 would require all antennas to be outside the fuse to get a clear signal. Just my guess thou.

Fun stuff.
Cheers.

i think the radio manufactures know something, I can't find a JR/spetrum 72 mhz radio on horizion's website anymore, and very, very few JR 72 mhz rx.
I have to correct myself, they are showing one 9303 and the JR website only shows the 9303 and a 10ch heli in 72

Didn't the 2.4 technology come out as being for park flyers? Short range applications?

Ch 41 is working great. The more people go to 2.4 the better it is for me. Never have had a problem with PCM an it don;t look like I will be for sometime. The price for a 9ch 2.4 Rx is sky high. I can pick up 149DP's an 319DPS Cheap Cheap. I'm loving it. 2.4 Makes me nervous.I have a friend over in Oklahoma,Just west of Ft.Smith Ark. Who flys right Off of Interstate 40. A private field with 15 members, They lost 7 27% an larger(One was a 50% Extra 260 with a 3W 212)last year to radar jaming equipment going down I- 40. One guy was testing his radio gear in a PT-40 after smashing his larger Edge 540 an smashed his trainer, cause his jamer was on in his truck.Still to many holes in 2.4 for me. 72mhz has not let me down yet.

Thats how it was introduced. Actually the car guys got it first. Then the short range air systems came out, now the full range systems.

If you're trying to say they are short range systems, thats true but they are still well within what we can see to control.

BarracudaHockey,

I'm not trying to knock the 2.4 technology. I think it's cool but there is one drawback to it, line of sight reception. When I taught myself how to fly RC (trial and error) I flew my Pilot 40 trainer behind a tree line by mistake. When I lost sight of it I didn't give up on it. I was able to recover it and bring it in for a landing. I think if I had a 2.4 system I would have lost it.

High frequency signals don't propagate around objects as well as lower frequency signals. I think that's why antenna placement in a 2.4 system is critical.


If they're using 2.4 in jets then range should not be an issue as they take up a lot of airspace.

If you're worried about range I'll just tell you this. I've had a 2.6m sailplane, to where I could barely see which way it was going, and pointed the antenna straight at it, and never got any signal loss.

You're right of course about the lower frequency signals progating differently but most of us don't fly behind trees often

Proper installation is critical in any radio installation, 2.4 just requires a slightly different approach than a 3 foot antenna hanging out of the fueslage, no dobut at all about that.

I'm also not knocking 72mhz systems, I still fly one.

There are a few things you LOOSE by going to 2.4 modules versus a 2.4 TX.

- Model Match

Model Match makes SURE that the setup you have selected on your radio, actually corresponds to the plane you are trying to fly.

I have a JR 10X with a 2.4 module, and I have several planes with 2.4 receivers bound to the module.

If I forget to switch the programming in the TX I could accidentally fly my Yak, with say, the setup for my Funtana, with disasterous results.

With Model Match, this cannot happen, the receiver must be bound AND the setup must match the plane.

- Failsafe

While the receiver provides failsafe settings, you have more extensive control over failsafe options with a 2.4gHz TX.

- Resolution

Step resolution available seems to be a bit higher with non-module systems.

There are a few other minor things that I cannot offhand remember...

Model match is only avaible on the JR/Spektrum radios. Futaba does not have this feature.

Airtronics new SD-10G radio has this feature as well, but it will only work with their 10 channel receiver.

Ken

Well since you brought up the abbrivations it is MHz that should be used for the frequency. The M is not from meter but from Mega as in 1 million...
(mHz would mean millihertz, 1/1000 Hertz)

I learn sumptin new every day.........what is it if the "z" is "Z"? Jest funnin' you.