Independent tests prove lack of frequency hopping with XPS

[XJet]

	Quote: Originally Posted by sweetpea
	Kiwi-- Of course if the new firmware holds true and creates a hop that is noticable (despite Xjet saying it cannot be done) and you then include the long long long awaited telemetry

Long-awaited is an understatement, considering that a good number of people opted to buy XPS pretty much solely because telemetry was promised right from the get-go.

	Quote:
	and satellites

To paraphrase JD -- XPS doesn't need satellites, it has a patented eight-element spherical antenna that does away with the need for satellites and diversity. Of course XPS will offer satellites but that's just to keep the stupid people (who don't believe the laws of physics can be broken) happy.

	Quote:
	......I'd say it is on par with the others in fixing its flaws.

But a *long* way behind the rest in delivering its day-one promises (hopping, telemetry, etc).

The others may have been fixing a few problems but XPS hasn't even got the system they originally promised (and people thought they were buying) out the door yet.

[jonkoppisch]

I bet if/when they ever show a video of the hopping.. It will probably be of the new modified/updated software version and not the one that everyone is using... Kind of like the xps receiver that is in his jet... All of us have top plug in receivers and are told to keep the wires from the antenna while his receiver that he uses has end pins...

[buttface]

,,,,,,,,,,

[buttface]

YUP..........

[XJet]

	Quote: Originally Posted by Cherokee Jim
	Will at least JD will come on a forum, when was the last time you heard anyone from JR or Futaba come on any forum? Do you ever wonder why manufacturers seldom get on forums?

Jim, for goodness sakes, lose the ugly big font (second request).

Reps from JR and Futaba appear on forums -- in fact they have dedicated support forums over at RCU -- just like JD has his at RCG.

JD says he can't get onto FG because of some technical issue or other (yeah, right! -- he can break the laws of physics but can't operate a web-browser?). It seems that JD doesn't like appearing in any forum where he doesn't have the right/ability to delete other people's posts.

As a result, he no longer appears on RCU or FG to defend the product or his outrageous claims for it.

I think that says a lot for his credibility and the contempt he has for independent evaluation of those claims.

[buttface]

.......

[Kiwi]

By the way does this forum have filters?


"Yea, ******************** SOB!"

Jim,

Yes we do mod this but our filters are only on expletives which can be circumvented with the use of asterisks or a mix of words that as a whole are offensive but individually OK.


WE have regular intervention from all the big players in our forums. They come in very quickly if someone starts stating information that is incorrect or down right bull dust.

In the case of Spektrum they were with us all the way in days when battery voltage and brown outs where an issue.

FUTABA were here with the 7C ZGUID giving us information and what they were doing about it.

Both the team FUTABA and team JR guys are always in here assisting if and when needed. Its just that they dont own the forum and are are not allowed to self moderate them. That is hardly conducive to free speech if there is such a thing on the internet.

Sweetpea.

Your a very defensive young guy and I admire your tenacity. When I said XPS is still the same box as it was two years ago I meant that fundamentally the OS is the same. The XPD is a bell and the new cases are a whistle. But the guts of the device, the spherical nuclear all encompassing antenna etc are the exact same.

The one and only issue with XPS that I see from a user point of view is that it is a single locked channel system with no antenna diversity, no possible way in the world to dodge interference or skirt it somehow.

The other systems (ASSAN is the exception but they dont claim to hop or try to get out od the way) ALL HAVE DIVERSITY.

If XPS would do what the manufacturer says it can do and show with repeatable certainty that it is a flexible and agile 2.4 Ghz radio transmission device perfectly suitable for RC use in all types and sizes of model airplanes then I will take my hat off to JD and the company. Competition is great, it drives technology, it creates a buyers market and normally it gets the customer a better deal in the end. But sometimes there are people who sell little bottles of snake oil at exorbitant prices claiming to cure anything and everything when in fact the oil in the bottle is for frying turkeys in.

As for testing the resistance of the others to the same test I have done it a dozen times but what I cant do is soak the entire band with sufficient noise to make even the slightest impact. I dont want to spend another $500 on the jammer as that is just wasting my money on a ten minute show and tell and then what will use it for?? Sort of a dumb device to be carrying around in my RC box I think.

So if your willing to let me show you FASST and SPEKTRUM working in the exact same conditions as I tested XPS I will post the video for you. But realize that with a single channel Rx (XPS) I will make it go into fail safe. The others will work perfectly because in the case of SPEKTRUM it has the second channel miles away from where I can swamp it and FASST just passes through it as if it does not exist.

I will try my best to get the video done tonight and post it for you.

[3ddd]

may be i need to go back and read the intire thread but i have been off line for two months and all i hear is the same old crap.it does this and it won't do that but these will.i think it is time to bury this tread and let the powers to be have it.i am open minded to real answers but the he said she said they said is really getting old. 86 pages of the same crap.just my two cents and only my thoughts

[Cherokee Jim]

Hello Kiwi and All,

Actually I had Filtering People out not words, that way I can filter out useless noise from the forum and have a better chance of getting just information information. Kind of like listening to the news - I don't want anyones Opinion - just give me the bare Facts!

Freedom Of Speech - Yes by all means - But while one is free to say what they want - Nobody is required to Listen!

As far as Futaba, JR, Airtronics, Hitech, or XPS coming on line to talk - I meant the Manufacture or designers themselves, not the field Reps.

I had good relations with JR for the ten years I worked in Japan, I went down to the factory and their sales office a number of times and I know they could communicate on this or any other forum if they wanted to.

Paul Beard is a good guy, he flies at our flying field and I know quite well about the Spektrum Power problems. I do own a DX7 radio, but I also own two Multiplex MC4000 radios that I wanted to convert to 2.4GHz - so since some people I know have used XPS with no problems I am checking out XPS.

I bought a simple 2.4GHz SA, purpose designed for the 2.4GHz band for under $100 dollars from Dunehaven Systems which also requires a Micro computer - USB link product, the Arduino Diecimila (which is a general purpose Micro computer based on the AVR series of micros).


Dunehaven Mini Spectrum Analyzer:

http://www.dunehaven.com/minisa.htm

Arduino Micro Computer Board:

http://www.arduino.cc/


When one puts the PC SA program into Peak Hold mode one gets some interesting results. Once I believe what I think I am seeing and I am able to confirm it at work with another SA I will attempt to record and post it.

Curse these New Technologies - I am forever getting into the Technology and Losing Valuable Flying Time!

The Font that I use, Comic Sans and size 4, stays - if it upsets you then don't read what I have to say. I feel more people will find it easier to read - myself included

My personal bet is that Sanwa/Airtronics will have one of the better systems out when the dust settles. Their designs have always been very good on the RF end of things. Multiplex may will come out with a 2.4 system but it will be a long ways down the road and only after they done an exhaustive comparison of the different systems. Right now I hear that Multiplex is not convinced that there is a Need for a 2.4GHz system

It does seem to difficult to have a technical discussion on line without it eventually turning into a Cat and Dog Fight over some useless issue.

Now for Graupner - I am sure they must have done enough testing to feel comfortable with XPS. They have been in this business much too long to Jump Ship without having a good idea of what they are jumping into.


Happy Flying,
Cherokee Jim

[XJet]

	Quote: Originally Posted by Cherokee Jim
	Actually I had Filtering People out not words, that way I can filter out useless noise from the forum and have a better chance of getting just information information. Kind of like listening to the news - I don't want anyones Opinion - just give me the bare Facts!

Well that's exactly what this thread is all about -- separating the hype and opinion from the facts. So far, the only facts we've got come from those who have sat down with an XPS system and *tested* it. The rest is just manufacturer's hype (which JD is unwilling or unable to substantiate) or the opinion of a new influx of FG members who say they have flown the system without problems.

I'm not saying that those opinions are without merit but, from a scientific perspective, they only constitute anecdotal evidence. Millions of people use Windows XP every day without encountering a bug -- but that is not proof that the product is bug-free.

	Quote:
	As far as Futaba, JR, Airtronics, Hitech, or XPS coming on line to talk - I meant the Manufacture or designers themselves, not the field Reps.

I think you'll find that the only reason JD himself (sometimes) appears in *a* forum at RCG is because XPS is a shoe-string operation that can't afford any field-reps -- so JD *is* the field-rep.

I suspect that the designers employed by JR and Futaba are actually busy designing new systems and, since the average RC flier isn't going to understand designer-level tech-speak anyway, there'd be absolutely no point in them participating in an online forum. JR and Futaba have people who are paid to do that job.

	Quote:
	I had good relations with JR for the ten years I worked in Japan, I went down to the factory and their sales office a number of times and I know they could communicate on this or any other forum if they wanted to.

But why would/should they? They have a world-wide network of distributors/dealers whose job it is to act as an interface with the market.

JD's market is *tiny* compared to that serviced by JR/Futaba. It makes no sense at all to have key people from the factory tied up in dealing with consumer issues. It's not only more sensible but really the only practical solution to delegate that role to people who can then report back to the factory as/when required.

	Quote:
	The Font that I use, Comic Sans and size 4, stays - if it upsets you then don't read what I have to say. I feel more people will find it easier to read - myself included

If you're eyesight is a bit weak, why not just change the default typeface/size that your browser displays. Then *everyone's* post will appear as Comic Sans size 4 if you want it to. It's a win-win!

	Quote:
	My personal bet is that Sanwa/Airtronics will have one of the better systems out when the dust settles. Their designs have always been very good on the RF end of things.

Sanwa's RF side seems okay and it is FHSS which is good. The only problem is that their current 2.4GHz transmitters lack a few features (such as expo on rudder for instance).

	Quote:
	Right now I hear that Multiplex is not convinced that there is a Need for a 2.4GHz system

And that's not a stupid perspective. The rush to 2.4GHz has become a stampede and people forget that it really is a chunk of spectrum which is a real battlefield. No licensing, no real control over the gear that's being used, widely variable power levels and bandwidths plus the sporadic appearance of some very nasty noise levels in some locations.

People who believe that 2.4GHz is always a better solution than narrowband will eventually (and probably to their cost) discover that this simply isn't the case.

Spread spectrum is the equivalent of wearing a pretty good flak-jacket but 2.4GHz is like the front-line in WW1. Ask yourself, if there's a fire-fight raging, would you really rely on a flak-jacket to save your life if you went for a strol through no-man's land?

Most fields are just fine, but some will be marginal at best for 2.4GHz systems and with the growing proliferation of legal and illegal devices on this bit of the band, things will only get worse over time.

	Quote:
	It does seem to difficult to have a technical discussion on line without it eventually turning into a Cat and Dog Fight over some useless issue.

So long as we stick to facts we're fine. The problem is (in this case) that XPS are making lots of wild claims that simply aren't true. If they were true then they could be backed up by proof from XPS but they're not.

We have no 3D radiation maps of the mythical 8-element spherical antenna and MaxStream deny its existence -- yet XPS tells us to simply believe their claims.

We have no evidence (other than hearsay and anecdotal reports) that XPS has any useful level of frequency agility and even XPS's own promise to deliver that proof has failed to appear -- yet XPS tells us to simply believe their claims.

But those who are XPS-faithful scold anyone who dares to question the claims of XPS, demanding "facts" to prove that JD is wrong.

There's a lot of religion going on in this debate but it's all on the XPS side.

	Quote:
	Now for Graupner - I am sure they must have done enough testing to feel comfortable with XPS. They have been in this business much too long to Jump Ship without having a good idea of what they are jumping into.

I'd dispute that.

Graupner found themselves short of a product when 2.4GHz took off. They couldn't effectively market Spektrum because of EU rules and regs regarding power levels and spectral density and the other 2.4GHz products already had distributors. For them it was XPS or nothing and I'm picking they figured *anything* was better than nothing.

I would not be surprised if Graupner were already regretting their association with XPS since there are a growing number of customers who are demanding a refund for their XPS/IFS system on the grounds that false claims were made for it. The consumer-protection laws in Europe are a lot more stringent than in the USA.

The last I heard (and I openly acknowledge that this is effectively just hearsay) was that Graupner were pushing XPS as a surface-radio now and were looking for a new 2.4GHz option for aircraft systems.

[Cherokee Jim]

Quote:




Right now I hear that Multiplex is not convinced that there is a Need for a 2.4GHz system

And that's not a stupid perspective. The rush to 2.4GHz has become a stampede and people forget that it really is a chunk of spectrum which is a real battlefield. No licensing, no real control over the gear that's being used, widely variable power levels and bandwidths plus the sporadic appearance of some very nasty noise levels in some locations.


I agree here - In one sense it does make sense to let the dust settle a little to more clearly see the path.

I never had technical problems with Multiplex's radios - The only problem I ever had with them was the usual suspect Batteries! Batteries are based on a chemical process and when we think they are just sitting there doing nothing --- Something is still going on.

Why are people jumping on the 2.4 bandwagon?

The next Best Thing

No worries about being shot down.

Faster response.

The Lemming Effect.

I am sure there are many more possible reasons but for my self, I spend a lot of time in the pits at times and other people just get tired of waiting for the frequency pin --- will mostly old Dead Stick Dave --- An interesting Character, old Dave started out in control line stunt and combat like my self --- Just fly until the gas runs out -- then land!

Happy Flying,
Cherokee Jim

[Gordito Volador]

Lemming Effect, now that is something I can finally agree with! I wonder how many of us there are?

[sweetpea]

	Quote: Originally Posted by Kiwi
	Sweetpea. Your a very defensive young guy and I admire your tenacity. When I said XPS is still the same box as it was two years ago I meant that fundamentally the OS is the same. The XPD is a bell and the new cases are a whistle. But the guts of the device, the spherical nuclear all encompassing antenna etc are the exact same. The one and only issue with XPS that I see from a user point of view is that it is a single locked channel system with no antenna diversity, no possible way in the world to dodge interference or skirt it somehow. The other systems (ASSAN is the exception but they dont claim to hop or try to get out od the way) ALL HAVE DIVERSITY. If XPS would do what the manufacturer says it can do and show with repeatable certainty that it is a flexible and agile 2.4 Ghz radio transmission device perfectly suitable for RC use in all types and sizes of model airplanes then I will take my hat off to JD and the company. Competition is great, it drives technology, it creates a buyers market and normally it gets the customer a better deal in the end. But sometimes there are people who sell little bottles of snake oil at exorbitant prices claiming to cure anything and everything when in fact the oil in the bottle is for frying turkeys in. As for testing the resistance of the others to the same test I have done it a dozen times but what I cant do is soak the entire band with sufficient noise to make even the slightest impact. I dont want to spend another $500 on the jammer as that is just wasting my money on a ten minute show and tell and then what will use it for?? Sort of a dumb device to be carrying around in my RC box I think. So if your willing to let me show you FASST and SPEKTRUM working in the exact same conditions as I tested XPS I will post the video for you. But realize that with a single channel Rx (XPS) I will make it go into fail safe. The others will work perfectly because in the case of SPEKTRUM it has the second channel miles away from where I can swamp it and FASST just passes through it as if it does not exist. I will try my best to get the video done tonight and post it for you.

Just for the record....Spektrum and FASST haven't done anything more fancy than XPS in regards to upgrades.

Spektrum--under the table upgrade that changed how it looked for freqs when a brown out occurred. Did nothing to stop the brown out or decrease its value. If it wasn't for the R/C forums no one would know you could do it.

FASST--Out in the open (good job there) they will reset your radio off the Zguid but that is still clouded in whether or not its a perm fix. You have other countries getting a different version of the fix than the US. Which is better or correct?

I would definetaly say that of these 3 manufactures that non of them has done a superb job of fixing their own issues.


As for your tests Kiwi........don't buy more equipment. Just post the vid of you doing the same thing you did to XPS to the others. so that would mean putting Spektrum on and putting the same power on one freq. Then slowly bringing it up and from the side etc. Then doing it again to the other freq it uses. For FASST I would just pick a freq in the front, middle, and end of the spektrum and do the same thing.

I expected these 2 to pass, but wanted you do it just to make sure that there wasn't something intrinsic in the test that may cause all to fail. Posting the video seals the deal just like everyone says it does with XPS.

[pilot232]

To Cherokee Jim,

I own a Multiplex mc4000. I converted it to Spektrum with help from Paul Beard. Nine chanels and it works beautifully. Take the following link if you are interested.
I used to fly XPS but was not comfortable with the lack of antenna diversity or apparent lack of frequency aagility.

Link: http://www.rcgroups.com/forums/showt...c4000+spektrum

Warm Regards,

Travis

[Kiwi]

Sweetpea,



Just back in from my shop and I finally got everything you want to see done. I have the video but will do one or two minutes shoot tomorrow to show you what happens.

Rather than leave you hanging by the neck however here is what took place and the results.

Tonight I set up four different radios.

Spektrum 7
Futaba 8UAPs with XPS
Futaba 8UAPs with Assan
Futaba 8UAPS with TM7 FASST module

Plus I ran my 14MZ on 2.4 to help create more noise.

Noise was generated using the AIRHORN from http://www.nutsaboutnets.com/ and it was generated in pulse mode and fixed.

The scanner was the Wi-Spy from http://www.metageek.net/.

XPS base line test. ( I needed something to set a goal)

OK first off I set the fail safe on the XPS so I could see it react as opposed to last time just waiting for it to fail. This time running just the XPS with the airhorn sending 5 seconds bursts over the 11 WiFi channels XPS went straight into lockout, it did not failsafe. It just froze up until the scanner had moved at least three channels away from the selected channel then it came back to life again. Pretty much what happened last time but just a little more conclusive.

ASSAN

Set up the same parameters as the XPS and same results. ASSAN locked up instantly there was strong noise on its chosen channel and it performed exactly as did XPS.

SPEKTRUM.

Same tests as above with the noise being generated over the spectrum. No noticeable impact of the controls so I added a video camera signal and turned on every other radio system I had. That is there were two FASST systems running, XPS and ASSAN. Spektrum never took a hit or showed the slightest evidence of any signal corruption. The video signal chosen exactly overlapped one of the SPEKTRUM channels as well so it was taking a serious beating. Nothing happened. 100% did not glitch or move.

FASST

Same scenario as the first XPS test. Unit was the TM7 transmitter module and 607FS receiver. Again the scanner showed it moving rapidly and using every nook and cranny in the spectrum. I subjected it to the all radios on test, video transmitter, and airhorn. I turned the radio on and off and it reconnected but I would not do this as a test at the field. It did not hook up at a pace that would save your butt. FASST behaved exactly as did SPEKTRUM. Solid, no glitches, nothing untoward at all.


Conclusions.

The conclusion and I'm not testing this stuff anymore is that ASSAN and XPS while seriously different vegetables perform about the same. They both failed and lost communication in seriously noisy environments. They both did not go into fail safe but locked out instead. Now that could possibly be a fault of the tester not setting the system up right. I admit that could be a fault but when I turn the radio off the servos went to low throttle were I had them set. With the noise they just locked up.

Now these conditions were horrendous for any radio system to survive but FASST and SPEKTRUM did and there was no glitching, no jerky servo movement. Plain fact is unless you had the scanner you would have thought they were in clean air.

The videos will take a while to cut and render as its a very long process. I use a SONY digital HDD 1080i camera and I have to change that format off the camera to give me an editable format for the MAC. A five minute video takes me about two hours to convert and render in a format you guys can see clearly.

However for my own peace of mind I can absolutely prove to one and all that ASSAN and XPS wont work in a noisy environment. I can prove that I cannot make FASST or SPEKTRUM fail in the exact same conditions as the previous two failed in.

I know what I will fit in my planes if and when I go to 2.4Ghz. There are two good choices so far. I'm sure more are coming like the Weatronics and the AIRTRONICS.

I'm working on the vids guys as fast or is that as FASST as I can. But its done, I'm happy the results were repeatable time after time. This was not luck or a flook. What I got in the end was real.