Topic: 2.4Ghz system?

Steve, I'm not exactly sure what you mean by "modern communications protocols" or "just" PPM?

But it must be said that most of the opposition's sets do offer modern communications protocols and not just PPM..... 

Ooh, fighting words, Steve! Of course you overlook the detail that Multiplex were the FIRST to market a PCM set. After this they recognised its limitations and decided that the better technical approach was to revert to PPM but use advanced DSP technology in the Rx (based on the excellent Paul Berg concepts) which provide as good or better communication integrity but without the restriction of proprietary PCM protocols and formats. So Multiplex have moved well BEYOND the primitive PCM technologies still used by the less advanced manufacturers...



PDR

PDR,

You took the words right out of my mouth!

And we'd better not mention the fact that Futaba are using a version of software they originally produced under licence from Multiplex back in 1984. Ooops, I just did.

And, just for the record, Multiplex were also the first to market a UHF set some time before the Reftec and Cotswold Controls sets appeared.

What hasn't been mentioned is that the SX is so simple to programme. I'd never programmed a Tx before the SX. Took me about 2-3 hours including a dry run without the rx switched on. As I've mentioned before my flying instructor tried for nearly three hours to get a loaned futaba seven channel Tx to work with my (then) flap and aileron winged glider to get crow brakes etc.. Not a chance, he showed me how he would do it on his profi, took about thirty seconds! I then did the same on the SX.. piece of urine. 

Personally I'd say that for a newcomer to programable transmitters both the Futaba and Multiplex systems are equally easy/difficult to program (never used a JR Tx for anything significant, so I can't judge). Where the Multiplex scores is the ease with which it can do more complex things. The Multiplex sets offer more *powerful* and flexible programming, but make using this extra power much easier than with the futaba sets IMHO. Examples would be the 4-servo glider wing or the use of coupled flapperons and elevons (ie twin elevator servos) on a 3d model. Programming and calibrating these on the futaba sets is far more complicated than it is using the multiplex approach, although were really talking about the comparison between FF9c and Evo9/12 here rather than the FF7/6EX vs Cockpit Sx here.

PDR

Fair comment PDR.

The Evo 9 and FF9 are indeed in the same league, and aimed at similar users. But as you yourself have found, once you've used Multiplex's software in depth, it really does have an edge over the competition.

And we'd better not mention the fact that Futaba are using a version of software they originally produced under licence from Multiplex back in 1984. Ooops, I just did.

I want to get back to the "debating over a pint" tone, because we all know that people get evangelical over their own sets. So I would be happy to list some of the things I *don't* like about my multiplex set - I'm talking Evo rather than Cockpit here.

1. The charger socket is unreliable. I don't know how they've managed it but they've made a standard DIN socket intermittant, and then compounded the problem by provding no "charging" indicator. I'm in the process of putting a second (futaba style) charging socket on the Tx, with a "charging" LED.

2. Multiplex's view that you only need one EXPO rate [per control] is frankly barking - I like to have different expo settings with different rate settings. There is a work-around in which you create a mixer with different 5-point curves for each flight phase (or on a switch, or whatever) but it shouldn't be necessary.

3. I'd like to be able to rename the flight phases rather than selecting from a a pre-defined list.

4. Fitting the long sticks (with the stick-mounted buttons) is something that keyhole surgeons would approach with a degree of trepidation! Feeding the wires down through the sticks is very fiddley.

5. I'd like to be able to have the antenna at a true 90 degree position rather than the "normal" and "nearly 90 degrees but canted a bit to the left" settings.

6. I'd like to be able to define the output of one mixer as the input to another, but this is an obscure requirement which only the real anoracks of flight control system designers would find a use for so I accept it's not really a market requirement (but I believe you can do it on their Profi 4000).

So it's not perfect, but on balance I still find it very, very good - and you only really get into just HOW good it is when you come to use it. We've covered a lot of the obvious things, but the less obvious ones are stunningly useful. For example the "digi adjustors" ("DAs" in multiplex-speak); the two rotary knobs at the top of the Tx that are essentially used to navigate programming menus, are also assignable "widgets" for certain things. So what? Well if I have (say) coupled elevator with flaps to correct the trim change, or coupled aileron & rudder, or tail rotor mixing on a helicopter I can assign the mix-ratio to one of these DAs. I then go for a test flight and I can tune this mixing to the required value in ONE FLIGHT rather than having to fly, land adjust, repeat until right. I don't believe this is possible on any other make of Tx and it's an absolute corker of a feature. And it's not just mix ratios; it can be done with rate settings, expo settings, travel limits - indeed anything that's a numerical value in the software. And once you have your desired value you simply de-assign the DA and the value remains static. I suspect this would make setting up a complex helicopter or an F3A model much quicker.

But now I'm getting evangellical - sorry!

PDR

Nice one PDR, the last bit about using the controls for fine tuning in flight is exactly what I do on my 9z, usually aileron differential amount, I can adjust in flight until I get the flight characteristic that I want (not easy for me  ) and then lock the setting when it's back on the deck.

Thanks for the Multiplex insight, still going JR. 

Regards - J

Nice one PDR, the last bit about using the controls for fine tuning in flight is exactly what I do on my 9z, usually aileron differential amount, I can adjust in flight until I get the flight characteristic that I want (not easy for me  ) and then lock the setting when it's back on the deck.

Thanks for the Multiplex insight, still going JR. 

Regards - J

Of course the 9z is the one that uses the licensed Multiplex software design...oops, I'm doing it again - sorry!

PDR

2. Multiplex's view that you only need one EXPO rate [per control] is frankly barking - I like to have different expo settings with different rate settings.

yeah that is silly.  my eclipse 7 (hitec) lets you have different expo (and you can have either negative or positive) for each flight phase.

then go for a test flight and I can tune this mixing to the required value in ONE FLIGHT rather than having to fly, land adjust, repeat until right.

Sweet. that would help a lot when setting up things like crow breaks and spoilerons.

Of course the 9z is the one that uses the licensed Multiplex software design...oops, I'm doing it again - sorry!

PDR

Well if thats an example of Multiplex software it's crap! The 9z is very flexible, great when you get to know it but an absolute pig when you first start. 

Regards - J

Well if thats an example of Multiplex software it's crap! The 9z is very flexible, great when you get to know it but an absolute pig when you first start. 

Regards - J

  you're hilarious, now go and buy your JR set and stop bothering us as you're clearly not interested in MPX for anything other than picking a fight.   

SP (who still hasn't read the manual for his evo coz it's that easy to use    )

Ooh, fighting words, Steve! Of course you overlook the detail that Multiplex were the FIRST to market a PCM set. After this they recognised its limitations and decided that the better technical approach was to revert to PPM but use advanced DSP technology in the Rx (based on the excellent Paul Berg concepts) which provide as good or better communication integrity but without the restriction of proprietary PCM protocols and formats. So Multiplex have moved well BEYOND the primitive PCM technologies still used by the less advanced manufacturers...

One of these days I must try a PPM/IPD receiver and see how it compares to the JR RS77S's and Schulze Alpha's that I use at the moment. Where I suspect that Multiplex did benefit when they dumped PCM is in being able to use the resources that other manufacturers spend on supporting multiple protocols on other features in their transmitters.

It will be interesting to see what Multiplex do if they do being out a 2.4 GHz set. Will it be a Spread Spectrum PPM or a Spread Spectrum PCM ? If it's the latter, it will be interesting to see how they spin it.

Thanks for the Multiplex insight, still going JR. 

I have a JR PCM9XII and I am very happy with it.

Steve

One of these days I must try a PPM/IPD receiver and see how it compares to the JR RS77S's and Schulze Alpha's that I use at the moment.

Muliplex IPD, Shulze Alpha, Hyperion DSP and Berg DSP all use the same DSP techniques and algoirthms, originally developed by Paul Berg and licensed to the others. I believe the Multioplex IPD implementation has a slightly more sophisticated fail-safe interface, but this may be a false impression because I've never studied them in any great detail. I don't actually have any Multiplex IPD receivers - I use mostly Schulze but with a smattering of my older Futaba PPM ones.

It will be interesting to see what Multiplex do if they do being out a 2.4 GHz set. Will it be a Spread Spectrum PPM or a Spread Spectrum PCM ? If it's the latter, it will be interesting to see how they spin it.

Why should they need to "spin" it? The principle advatnage of the PPM/DSP approach is that it's not a proprietary standard, so there is compatibility between different manufacturers' equipments. All 2.4GHz systems use proprietary standards, so there is no pre-existing standard to maintain backwards compatibility with, so the advantage is reduced. Thi issues around types and sources of interference, and susceptabilities to them, are very different at the microwave end of the spectrum so the technical merits of the different data systems won't necessaily be the same.

PDR

you're hilarious, now go and buy your JR set and stop bothering us as you're clearly not interested in MPX for anything other than picking a fight.   

SP (who still hasn't read the manual for his evo coz it's that easy to use    )

I have asked questions regarding what makes Multiplex 'head and shoulders' above the rest as has been said. Lots of information has been forthcoming, lots of info I didn't know such as Multiplex involvement in Tx software for other manufacturers.

I am not picking a fight anywhere, merely discussing merits or otherwise of this equipment.

Sorry it seems to rattle your cage but.... tough

Regards - J

Well you still keep comparing the Cockpit SX to the FF7.  Compare it to the 6EX then tell us how it isn't "head and shoulders" better.

I can't sensibly discuss the technical aspects of the Multiplex gear. However, I have owned the Pico and the SX and have to say that the clean design and ease of programming are very attractive to me.

That said, I have had the odd "issue" with the programming, but these have resulted from an inadequate user manual, rather than the transparency of the system.

I'm very keen for Multiplex to launch 2.4 GHz stuff. I will be buying it in preference to JR, Futaba et al.........provided that they don't take forever to get the stuff onto the market. I should probably be happy to hang fire for a year or so, before committing to 2.4 GHz. Is there any prospect of Multiplex producing a system within this time frame?

seems a bit unlikely at the lower end of the market, seeing as they've just brought out the SX on 35mhz. bizarrely,they don't sell this set at all in the USA. for once we are better off. They have to make do with the optic 6 and eclipse 7 from hitec/mpx.  Apparently the synth modules have had loads of problems.  hitec's solution was to slap some electrical tape on it 

I can't see it happening for a while.  It's not just the electronics, it's the cases (for the stubby aerial), that would need to change.

I can't see it happening for a while.

I can. I strongly suspect that Multiplex management are putting a lot of effort into getting a 2.4 GHz version of whatever their best selling model designed and tested. The only new transmitters that I have seen this year (at a fixed wing only club with 80 ish members) are 2.4 GHz. All but one of these transmitters are DX7's and a lot of people have seen them performing flawlessly and are considering 'going 2.4'. I would love to see the figures for transmitter sales by model for this year.

Steve

yeah, when the mainstream JR and Futaba sets hit the shops, you'll more. I've only seen one (i think) DX7 at my club, but then it's gliders only and the DX7 isn't much cop for all our gliding mixing needs (especially 4 servo wings) - it can do it, but you need to fiddle a lot........

Well you still keep comparing the Cockpit SX to the FF7.  Compare it to the 6EX then tell us how it isn't "head and shoulders" better.

Mark, I haven't done any comparisons at all, merely asked what makes Multiplex head and shoulders above the rest and if it's so good why isn't it 'the' mainstream transmitter.

Regards - J

6. Full 4 servo glider wing capability.

I don't see why this can't be done on the FF7

That was the one I noticed, regardless of your previous posts I would still urge you to compare the entry level Cockpit SX with the equivalent Futaba offering.

Incidentally I have never owned any Multiplex equipment and for the 20 odd years prior to getting my DX7 have always used Futaba.  The 6EX I have feels little better in the hands than those ones that come with Hong Kong RTFs and it's features and programming are almost identical to the FF6 I bought many years prior to it (save for the addition of expo and a whopping 3 extra model memories...whoop-de-do!).  I have also briefly fondled a Cockpit SX and it was rather more confidence inspiring.  I've never needed a high end set so can't offer any comparison there but from what I can see Futaba have somewhat dropped the ball when it comes to the needs of an average flyer like me.

I was responding to someone elses comparison!

I've always had Futaba, currently 2 x 9z's, at Christmas I bought a DX7 to find out what all the fuss was about and hence moving to the JR high end 2.4GHz when avaliable. I was curious about Multiplex but nothing I've heard has changed my mind so far.

Regards - J

Muliplex IPD, Shulze Alpha, Hyperion DSP and Berg DSP all use the same DSP techniques and algoirthms, originally developed by Paul Berg and licensed to the others.

That is interesting and has saved me from possibly buying an IPD receiver out of curiosity. In my experience, the JR RS77S PCM receiver is better (and cheaper) than the Schulze Alpha's that I have. If I get hit by a burst of interference (or forget to put my antenna up  ), I know what I would rather have in the model. And it isn't the Schulze.

Steve

That is interesting and has saved me from possibly buying an IPD receiver out of curiosity. In my experience, the JR RS77S PCM receiver is better (and cheaper) than the Schulze Alpha's that I have. If I get hit by a burst of interference (or forget to put my antenna up  ), I know what I would rather have in the model. And it isn't the Schulze.

Steve

And yet Steve, I've heard of people having difficulty getting the alphas working (flybyday or someone else binned one a whort while ago I think?) but never, ever heard anyone say anything bad about a multiplex IPD. I have two of them and they are simply superb. 

Mark, I haven't done any comparisons at all, merely asked what makes Multiplex head and shoulders above the rest and if it's so good why isn't it 'the' mainstream transmitter.

Regards - J

There are loads of reasons why-marketing, chatting to fellow flyers and getting their views-and we all know they'll be different! Budget plays a part too. I think also there could be a 'type' of modeller that chooses a particular brand of beans,cars,cd players and indeed radio gear. Just assess the merits or otherwise and pays the money. I chose the SX (More or less committed to getting a DX7-being on two waiting lists) only after getting the pdf of both radios and finding, togther with comments on this forum, that it didn't support easily four servo wings. No contest really, especially after what I've mentioned previously.

And yet Steve, I've heard of people having difficulty getting the alphas working (flybyday or someone else binned one a whort while ago I think?) but never, ever heard anyone say anything bad about a multiplex IPD. I have two of them and they are simply superb. 

I don't have a problem with the Alpha's. It's just that I have found the little JR synth PCM receiver to be better. And cheaper. I use my Alpha's in gliders and RS77S's in anything with a fan.

Out of curiosity, I've just had a look at a couple of online shops assuming that I was a flyer with a few models and £300 to spend on a new transmitter and a few receivers. £300 translates to -

1) a Cockpit SX and three RX-7's
2) an JR 2720 and three RS77S's
3) a DX7, two receivers and four micro servos
4) a Futaba 6EX-FASST, three receivers and four standard servos

Which my hypothetical flyer would go for doubtless depends on what they fly and where (personally I would go for a JR PCM9XII and two RS77S  ), I suspect that a lot of the guys down my club will end up with 4.

Steve

i find the RS70 to be an excellent RX for the money. 

Hi again John

Perhaps if Multiplex had the manufacturing base and marketing budget of Futaba, they'd sell considerably more equipment than they already do. For a relatively small r/c equipment manufacturer (about 50 people are employed by Multiplex in Germany) they enjoy excellent sales in most of Europe, particularly in Germany itself, and have done so for 40+ years. They've also been at the forefront of r/c technology for quite some time, being the first company to develop things like proportional control (1963), digital servos (1968), interchangeable Tx frequency modules (1978), PCM modulation (early 80's), 10kc channel spacing (1979) first programmable transmitter (1976) etc. Not a bad showing for a company with somewhat limited resources, compared to the big boys.

The German FTZ telecommunications regulatons mean that new Futaba and JR equipment as you know it cannot be sold in Germany. It simply does not comply with the regs as they currently stand. To get round these regs, both Futaba and JR have equipment built to FTZ standards specifically for sale on the German and other European markets. Futaba market their "German" sets as Robbe equipment, while the equivalent JR gear is branded as Graupner radio. These sets also have the "pizza box" European styling, presumably because German and other European buyers would shun sets not conforming to an accepted Euro "look".

The upshot of this John, is that Multiplex equipment is built to a standard far in excess of the minimum required. Multiplex radio equipment is used worldwide by the military for target drones and remote observation vehicles, such is it's reputation and reliability. Typically, in a ground range test with a fully collapsed Tx aerial, distances well in excess of 250 metres can be achieved. Multiplex themselves stipulate a minimum of 80 metres under ground range test conditions. Multiplex radio control equipment has been independantly tested (by a leading American r/c mag) as having just about the most secure rf link available. Surprisingly, HiTec equipment was found to have an rf link almost as good!

Hi Brian,
Thanks for that, more I didn't know! I never realised that Futaba and JR were restricted as it were in Germany, hasn't the common market harnonized all this yet?

Thanks for the condensed history and update.

Regards - J

Reason Hitec is so good is basically the guts in Optic transmitter is multiplex design.

No problem John.

I'm aware that you've probably still not heard anything to change your mind, but actually using a Multiplex set might well sway you.

Take PDR for example. He's stated openly on here that after being a Futaba user for 30 years, he made the switch to an Evo 9, and is now totally won over. PDR actually likened the FF9's software to a kiddies toy after using the EVO for a while! Seemed a tad rash at the time, but PDR isn't a man to mince his words.

I very recently purchased a secondhand EVO and I have to agree with PDR, the programming logic/layout is superb. I actually think I prefer it to my Mc4000 although it's obviously nowhere near as powerful, or ultimately as flexible.

Take PDR for example. He's stated openly on here that after being a Futaba user for 30 years, he made the switch to an Evo 9, and is now totally won over. PDR actually likened the FF9's software to a kiddies toy after using the EVO for a while! Seemed a tad rash at the time, but PDR isn't a man to mince his words.

I had noticed this, he must hide it well 

No, still going to stick with the JR route I think because I now have quite a few Spektrum receivers. So, unless Multiplex bring out a 2.4GHz Tx, small sized format that will talk to the Spektrum Rx's BEFORE the JR ones hit the market I'll be staying with my decision.

Regards - John

I've just noticed this https://shop.graupner.de/webuerp/servlet/AI?ARTN=23206.  Tempting, very tempting.  Come on Multiplex, I may break soon!

Hi Chris

An interesting development indeed. However, I'd still be tempted to hang on. Everything comes to he who waits.....

P.S. John, it's very unlikely any upcoming Multiplex 2.4ghz gear would "talk" to any other brand. The 2.4 scene doesn't seem to be going that way at all. It's my guess that Multiplex 2.4 gear will be different again from what's available just now.

It's my guess that Multiplex 2.4 gear will be different again from what's available just now.

You mean streets better Brian.   

Well Alex, for a few moments I did consider using the word BETTER instead of different, but I thought that'd be obvious enough to us Multiplexites anyway. 

Well Alex, for a few moments I did consider using the word BETTER instead of different, but I thought that'd be obvious enough to us Multiplexites.

 

P.S. John, it's very unlikely any upcoming Multiplex 2.4ghz gear would "talk" to any other brand.

Thats my assumptions too but the manufacturer that brings out a Tx that talks in all the other formats would surely be onto a winner.

I'm told on a regular basis how Multiplex are head and shoulder above the rest could this be what theyre up to?

Regards - J

Hi John

I doubt it. I should imagine Multiplex are keeping their finger very much on the pulse regarding 2.4ghz John. But Multiplex have never been too concerned in the past that their gear wasn't compatible with other makes of equipment. 

No, I think they've probably had 2.4ghz gear in the development stages for some time (In fact I'm certain of it), but what they're probably doing right now is working on what'll make Multiplex 2.4ghz gear stand out from the crowd. And be assured John, it almost certainly will.

Hi John

I doubt it. I should imagine Multiplex are keeping their finger very much on the pulse regarding 2.4ghz John. But Multiplex have never been too concerned in the past that their gear wasn't compatible with other makes of equipment.

No, I think they've probably had 2.4ghz gear in the development stages for some time (In fact I'm certain of it), but what they're doing right now is working on what'll make Multiplex 2.4ghz gear stand out from the crowd. And be assured John, it almost certainly will.

Time will tell, I'll watch with great interest.

Thanks for the comments chaps, it's been very enlightening in more ways than one.

Regards - J