2.4Ghz Spektrum Modules !!!!!!

[ChrisB]

Of course, the ultimate would be that the Futaba 2.4G system was compatible with the Spektrum one... Then we could buy the spektrum module now, and have the choice of receivers later.

Was that a pig I saw flying past the window?????

Exactly,that will never happen,it will be a case of JR,if they do one,Futaba or Spektrum

No problem really,there are hundreds of makes of audio equipment,white goods,cars,which company you bank with,who are you insured with


Choice is never a problem

[fatmantom]

hi
just to hi-jack this thead for a sec (i didnt feel it was worth its own thread), there is someone very local to me selling a futaba 9cap tx for £110. is that a bargin??

i already have a jr 2610 is it worth upgrading to the futaba?
thanks
tom

[robgt]

£110 for the Futaba 9C is a good price.
I also think it's better than the 2610 - but bear in mind that any receivers you might have (JR) may need changing for futaba ones.
Cheers,
Rob

[rambo]

only if it is PCM....lol

[jimbob]

...and even if its not PCM, you'll need to change your channel order (I'm pretty sure anyhow)

[rambo]

lol, yeh, you definitely need to change the channel order.....

channel 1, 2, 3 get moved up one, but the rudder stays the same...

so, ailerons become 2, elevator becomes 3, and throttle goes back to 1......simple

[rambo]

lol, just realised I was talking about JR tranny and Futaba receiver...lol

If you are using Futaba tranny and JR receiver then the channels will change, but not sure how.....

I spose its just the opposite to what I said above

[Disc]

Guys ripped from the BMFA Website read it and consider the modules as well...

Ripped from BMFA Website


As someone who has been designing R/C equipment for over 30 years, perhaps I can add a little to this discussion and clear up some misconceptions......

The way that information is transmitted in the 2.4 GHz band is completely different to anything we have used before. Whether it be 27 MHz, 35 or even 459, we have always had to work within very narrow channel spacings, usually 10 KHz (on 35 MHz) or 25 KHz (on older 27 MHz and 459MHz). On 2.4 GHz, we have about 1MHz of bandwidth available for each channel! ie, each channel on 2.4 GHz gives us more bandwidth than ALL of the 35 MHz channels put together!

The upshot of this is that we can transmit data much faster, and we can also include "redundant" information for error checking.

However, to make use of this facility means that the whole encoding process at the transmitter is fundamentally different from anything previously used!

Whilst it is perfectly possible to design a plug in module for an existing transmitter, by doing so, you throw away many of the advantages of the new system!

The fastest data rate on a "conventional" system occurs when we use good old fashioned PPM. PCM is always much slower, as you have to transmit many more "pulses" per function, and the bandwidth restricts the rate at which you can transmit these pulses. This (plus the fact that PCM numbers have to be decoded back into variable width pulses) is why there is always a small but perceptible delay between moving the sticks and the servos responding in any PCM system.

So, to get the best out of a "module" 2.4 GHz system, you must set the Tx to PPM. The module will then measure the pulse widths, and re-encode this into whatever system it happens to be using. However, PPM only outputs at a rate of about 50-60 frames a second! A standard 2.4 GHz system is typically over ten times faster than this (maybe as much as a hundred times faster)! So using a module in a current transmitter is a bit like buying a V12 Jaguar, and then removing 10 of the spark-plugs!

The high data rate on 2.4 GHz is why pilots have been commenting about how responsive it feels compared to a standard 35 MHz system. Don't expect this to apply to a module system! At best, you will match what a PPM system can achieve, although there will be added security over PPM.

I can foresee a new generation of transmitters being made that will detect whether they are using 35MHz or 2.4 GHz, and adapt their encoding accordingly. But don't expect a current transmitter with a 2.4 GHz module to be as effective as a dedicated 2.4 GHz system.

Some other things to bear in mind: 35 MHz is exclusively for model aircraft use. 2.4 GHz is shared, just as 27 MHz and 459 MHz are. At the moment, this isn't a problem, as most 2.4 GHz usage is for things like wireless LANs on computers - not the sort of things you are likely to find on a flying site out in the sticks somewhere! However, this is no guarantee that this will always be the case! Nobody expected 2.4 GHz to end up being used for model control, and there may be someone else out there at this very moment, designing some obscure use for 2.4 GHz that hadn't occurred to any of us, but might have a major impact on our usage of it! Its SHARED, so we won't be able to complain!

Radio frequencies are tools, and just like any other tool, if you use the wrong one for the job, you will end up disappointed! I'm not knocking 2.4 GHz. I think its a wonderful step forward. But don't expect it to be a universal panacea for all the ills we *think* 35 MHz suffers from. Its a case of "Horses for Courses"!

--
Pete Christy

[3dbasher]

disc empty your inbox i'm trying to pm you

[Disc]

disc empty your inbox i'm trying to pm you

No

skype?

[3dbasher]

No

skype?

didn't think of that i'll call you in a sec

[Disc]

didn't think of that i'll call you in a sec

if we can get it to work

[3dbasher]

if we can get it to work

i'm back on.. spoke to paul for about 20mins must be your bloody mac

[Smoothound]

Works fine on my Mac, only problems I ever had are down to bandwidth and CPU usage and then all I get are odd dropouts which I also see on the PC as well