Eric.Henderson

Now that we have a veritable plethera of 2.4 gHz modules and radios draining our visa card reserves, I have been condsidering the compatability between manufacturers and within manufacturers.

As an owner of JR computer and Futaba computer radios I was attracted to the Spektrum modules. I have always enjoyed the way my computer radios would translate mode-1 into mode-2 for me. This has allowed me to both fly a lot of planes and help a lot of pilots that otherwise I could not because I was on the "other" mode!

As I understand it so far, I can put a Futaba Spektrum module in my 9 ch futaba radios and a JR Spektrum module in my 7,8 or 10 JR radios, then I can drive the same Spektrum reciever with either radio, once "mated" of course.

I think I know the answers to the next questions but I really would like to defer to those folks who really know about this stuff.

1. If I have a DX7, can I drive the 7 ch Spectrum RX that cames with the upgrade modules above?

2. Conversely, can I drive my DX7 RX with my "Spectrumed" Futaba and JR radios?

3. The Futaba FASST system is not compatable with any of the Spectrum RX's Right?

4. Can the new Futaba FASST modules drive the 2.4 RX of their entry level FASST Radio set.


With a considerable stable of JR and Futaba radios at my local fields it would be very helpfull if I knew for sure what answers to give when asked about the above.

Regards,

Eric.

P.S. Anyone know what is going on in the Internatinal (Outside the USA) arena as regards 2.4 radios?

JCINTEXAS

I've been a long time gone from R/C flying and just returning.
Question about 2.4 GHz.
Is any in this forum flying one of these new radios?
What is the general "consensus" on these (if there is one )?
Is 2.4 GHz "better"?
Any opinions on whether the Spektrum or the newer Futaba FAAST is the better system?
Regards
JC in Texas

Bob Pastorello

My Feedback: (198)

1. Yes,
2. Yes
3. NO, it is NOT compatible.
4. No idea

dirtybird

My Feedback: (5)

If you are just returning and have your options open be sure to go direct to 2.4GHZ. Its a much better system.
As to Spectrum or Futaba only time will tell. Spectrum is out and works. Futaba is still gearing up.

Geistware

My Feedback: (16)

Answer 3 should be right or yes.
JR uses frequency lock
Futaba uses frequency hop.

Bob Pastorello

My Feedback: (198)

Thanks... I modified my "NO" to "NO - not compatible".
Always confusing with a negative question.....
Does yes mean the "question" is correct, or does no mean the focus of the question is negative......
Glad we're on the same page about those differences, though.

LuckyArmpit

As for those questioning futaba's stake in the 2.4 gig world, I have the FASST system. And yes, it works perfectly fine.
Some are wondering why did futaba take the channel hopping deal. Probably because since they have been doing 2.4 gig in industrial settings which BTW
would have a heck of alot more interference than your rc field, they felt that their system was pretty much tested. Sure, the system takes 2 milliseconds to hop from
one chanell to the next.
Hehehe...do you all know how fast 2 milliseconds really is?
Anyways, I've been flying the FASST system for a month now. No problems no glitches. Done deal. Also, there are quite a few in the club with spectrum systems.
None of them have had any probs either.
Yes, the FASST radio doesn't have all the glitz and glamor that the DX7 has. But, it has enough for what I need and use. The nice thing about all the 2.4 systems is that
you aint gots to worry about who is on what channel. With some of the larger clubs or for you rogues that fly at parks and school yards, its a free for all on the 72 mhz band.

Dave...

Eric.Henderson

With the new JR and Futaba dedicated 2.4 GHz system announcements we now have similar "brand loyalty" choices to what we had before. The after-market /purchase modules for both systems allow us to upgrade our existing radios. If you don't include the Spektrum modules we are back to having like-work-with-like with the dedicated 2.4 GHz systems.
The Futaba guys can build a personal stable of FASST systems. The JR guys can do the same with their brand and Spektum modules. Looks pretty good for all of us.

Until I need a new radio system, it is no big deal. I have been here before. I was there when the UK switched from 27 to 35 mhz. That needed new TX's and RX's. Then in 1982 it was I switched from 35 to 72 hz. That time it was simply a case of buying new receivers and swapping out all of my TX modules. Not cheap, but not as expensive as buying new radios. This time around it will be the new TX modules and receivers route again.

I think that the only programming change that I will have to make is to swap from the PCM to the FM setting.

Your last point, "The nice thing about all the 2.4 systems is that you aint gots to worry about who is on what channel. With some of the larger clubs or for you rogues that fly at parks and school yards, its a free for all on the 72 mhz band.", made me think of a particular personal benfit that this new technology brings to me.

Not everyone out there is that well balanced, especially when it comes to any kind of feedback that they don't like. Said another way it is way too easy to get someone mad at you. I know that for some years I have had an RC stalker. I am sure that I have been deliberately shot down. Whether that is real or not is no longer an issue with our 2.4 GHz radios.

Regards,

Eric.

saitofreak

...safe until I fire up my EMP-Generator - he! he! The titanic was unsinkable...

Nah, 2.4Gig is great - I really look forward to all the manufacturers getting their product into the LHS. I agree that modules are the most flexible way to go, and would allow one to continue mixing brands. It's just more expensive.

Eric.Henderson

What is happening in the UK with 2.4 GHz? Are we on the brink of having one R/C model radio band for all of the countiues in the world??????


Regards,

Eric.

saitofreak

I'm glad to say that we have the Spektrum DX6 and DX7 in some of our stores but demand is high and supply is low. The Futaba 6EX is imminent. I think our brothers in the US are grabbing the first slice o' cake - so to speak! The frequencies and transmitter power are the same here in the UK, but the Frenchies are doing their own thing. They are the only exception in Europe, that i know of.
This may well end up being a worldwide band. Pretty cool

Eric.Henderson

AMEN!

For many years I dreamed of this happening. It was great for me when computer radios solved my mode-1 to mode-2 interaction problems, Now I can travel to see friends in other contries and still use my stuff. This is an order of magnitude greater.

Thanks for the reply.

Regards,

Eric.

Eric.Henderson

My Spektrum modules and 9 ch receivers came today.

I was already working with a DX7 so I eagerly set up my 10X and did a "bind" with the DX7 7000 RX. That went well.

Then I tried the 9 ch reciever with the DX7. That went well too! FYI - the two extra channels in the 9 ch RX do nothing. There is no life in the last two servos, nada! when you drive a 9000 with the DX7. No problem of course.

So, so far I have my desired compatability. I will try the modules in my 7 and 8 channel TX's and do the same. Should be good. [The Futaba modules are not available yet - I'll do that one when they come out]

What it means to me, in practical terms, is that I can set up a 7ch DX7 receiver with my mode-1 10X transmitter. Test fly what I have built and then program the DX7 TX for the mode-2 pilot/owner. One "bind" later and the plane is hooked up to his TX.

Regards,

Eric.

Silent-AV8R

Not quite accurate. The FASST system hops to a new channel every 2 milliseconds, it does not take that long to make the hop. The hop is virtually instantaneous. It happens 500 times a second.

felker14

My Feedback: (50)

No on question 4 unless you get 12z/14mz module.

Eric.Henderson

Just as an FYI - I took my 10X 2.4 conversion to the field yesterday for a bit of a show 'n tell and also to try it on an electric plane. "Electric" Harry, as he is known, has a T-34 on a DX7 with a brushless speed-cotroller and a BEC set-up that I wanted to explore with my 10X 2.4.

He is on mode-2 with a DX7 and I am on mode-1 with a 10X 2.4 conversion.

With a glow plane you tend to have a charging jack somewhere on the plane. If not there is probably a charging lead from the switch somewhere. Anyway on Electric Harry's plane we had no external lead to plug in the binding jumper lead. If you are using a BEC that feeds the power through the "throttle servo" lead you often don't have a switch in the circuit anyway and you are not plugged into the battery socket of the RX - most folks seem to just plug in the LIPO!

I was concerned that the electric motor might not like all of the binding that we were doing but it never sprang into life, which was very pleasing. I know the theory but there is nothing like testing to make me feel better :-)

To bind an R7000 using a BEC we had to plug the binding jumper directly into the bind/battery socket of the receiver. It worked immediately. (if you are swapping TX's a lot, I guess you could put an extension lead in the bind socket to make repeated binding a lot easier.

I then could then check the settings of his controls. His "settings" and my untried settings were compatible. The servos centered the same. I only had to reverse the rudder servo. The throttle behaved correctly from my radio. However, I did not get a flight in because he had just broken the prop and we did not have a replacement. Next time maybe.


Regards,

Eric.

Eric.Henderson

Thank you for the answer to Q4. I get asked a lot of questions like these and it really helps to have a good answer.

Regards,

Eric.

FliteMetal

FYI:To answer some questions jet jocks and natural finished warbird builders might have we have posted the results of an evaluation conducted by George Maiorana and two others using his TU4.

http://004edc4.netsolhost.com/fm__spread_spectrum.htm

The range was identical regardless of where the receiver and servos sat. The systems, all of them, were still working correctly when the evaluation team stopped the evaluation with the systems in normal flight mode. The evaluation was not measuring r/f strength of the SS systems. You will note that would have required electronic measuring equipment. It was and is the only desire to observe any physical difference in the operation of the servos under the conditions the SS systems were used.