Kiwi's XPS test results are up.

[XJet]

	Quote: Originally Posted by tadawson
	Obviously. But no matter what antenna is used, inverse-square losses still apply. - Tim

Not true Tim.

Inverse square only applies to an isotropic radiator. Directional antennas have a lower signal loss as a function of distance and directional antennas are not uncommon on the 2.4GHz band.

Flying into the path of a signal being sent using a directional antenna will also produce a rise in the noise floor at a rate *much* faster than the 11 second period XPS apparently requires to induce a hop.

[XJet]

	Quote: Originally Posted by tadawson
	Yet the guys at Boing have claimed to have been able to do so, and others have seen it function in flight. Data that I cannot disregard - video or not.

As I've said before -- I'm sure that under exactly the right conditions, XPS *can* be induced to hop, that really isn't the issue.

The issue is whether it hops when it really needs to -- ie: when encountering a strong interfering signal.

JD's explanation and described parameters prove that it won't hop under such circumstances, something confirmed in Kiwi's tests.

If JD says it won't hop in response to interference and Kiwi's tests confirm it -- what more proof do you need?

As has been said before -- XPS's hopping is somewhat akin to a car with airbags that will only deploy very slowly and even then, only when the car has been parked for at least 11 seconds. That's because these airbags aren't to save you in the event of a crash, they're there so you can comfortably rest your head on the steering wheel. Yes, such a car has airbags -- but are they any *real* use in a smash? Hell no!

The guys from Boeing may have seen these headrests come out but that doesn't mean they're of any use in a crash. Some guys may have actually used them when feeling tired in a carpark -- but they're still useless in a smash.

	Quote:
	Video is so easy to fake, that I find it to prove basically nothing

Dead right (although I hope you're not suggesting that Kiwi has doctored his vids). But JD's admission (at last) that XPS's frequency hopping was never intended to change channels in response to interference categorically proves that the original claims made for XPS were false and that what feeble hopping ability it has is useless as an interference-protection mechanism.

Come on Tim, surely even you can see the facts now.

[easytiger]

	Quote: Originally Posted by tadawson
	Yet the guys at Boing have claimed to have been able to do so, and others have seen it function in flight. Data that I cannot disregard - video or not. Video is so easy to fake, that I find it to prove basically nothing . . . . remember the guy with the vid TX that put out the hoax video that he got a hop? Looked just as credible as the rest . . . - Tim

"Come on Tim, surely even you can see the facts now."-Xjet

No, he can't. He does not want to see.

I once did a gig in Toronto that involved being in a room full of Holocaust Deniers. No matter what evidence, even eyewitnesses, these people had an explanation. Either the video was supposed to be faked, or the witnesses lying, whatever. They would go on and on, for hours, explaining everything away. Nothing would shake them. Do you know why? They truly beleive what they are saying. It's an odd aspect to human nature, people get a notion in their heads, and nothing can shake them from that notion.
So why are you debating Tdawson? If he does not "get it" at this point, he never will.

In the meanwhile, while Mr. Dawson's jury is still out, planes are still crashing. Another jet trashed the other day, another heli gone. Evidently, these damn aircraft either do not read the internet, or they just don't read the paid shill/fanboy part, I dunno.

[easytiger]

	Quote: Originally Posted by Kiwi
	Well looks like you have some knowledge of PNG that many others would not have picked up on. To know about the cargo cult means you have either read well or visited the place. Which one?? As for things hotting up Jon it was only a matter of time. One way or the other the nuts and bolts of the XPS system will come out.

Sure, I got three degrees in Physics, Nuclear Science, and Phrenology from UPNG when I was sixteen!

[tadawson]

	Quote: Originally Posted by XJet
	Not true Tim. Inverse square only applies to an isotropic radiator. Directional antennas have a lower signal loss as a function of distance and directional antennas are not uncommon on the 2.4GHz band. Flying into the path of a signal being sent using a directional antenna will also produce a rise in the noise floor at a rate *much* faster than the 11 second period XPS apparently requires to induce a hop.

Now I think that you are the one smoking crack . . . much like there is no such thing as an isotropic radiator, there is also no known antenna that has zero divergence to the beam. And as you get further away, the beam widens, and inverse square DEFINITELY applies. All that the directional antenna gets you is more power going in a given direction - it falls off in exactly the same way, and the additional signal you get at the far end is due to more ERP at the transmitter, nothing more . . . it's all about gains, not changes in the laws of physics with regard to signal attenuation over distance . . .

- Tim

[tadawson]

	Quote: Originally Posted by easytiger
	"Come on Tim, surely even you can see the facts now."-Xjet No, he can't. He does not want to see. In the meanwhile, while Mr. Dawson's jury is still out, planes are still crashing. Another jet trashed the other day, another heli gone. Evidently, these damn aircraft either do not read the internet, or they just don't read the paid shill/fanboy part, I dunno.

Yes, I see all the facts . . . and XJet does *NOT* have a lock on facts - just some strong opinions.

Oh, and I guess that all the Futaba and Spektrum failures out there aren't happening either, at least not in your world? Damn shame that Futaba stuff can't take something as simple as the levels of heat at a lot of southern flying sites.

To make it sound like XPS is the only one with problems really makes you sound like a total dips**t . . .

My difference is I choose to both *look at* and *evaluate* the evidence, as opposed to just foam at the mouth and regurgitate and spew things that cam from others and that may not actually be factual . . . Your attitude clearly makes you a non-credible source of information - objectivity went out the window a LONG time ago in your camp!

- Tim

[Tin man]

	Quote: Originally Posted by tadawson
	Yes, I see all the facts . . . and XJet does *NOT* have a lock on facts - just some strong opinions. Oh, and I guess that all the Futaba and Spektrum failures out there aren't happening either, at least not in your world? Damn shame that Futaba stuff can't take something as simple as the levels of heat at a lot of southern flying sites. To make it sound like XPS is the only one with problems really makes you sound like a total dips**t . . . My difference is I choose to both *look at* and *evaluate* the evidence, as opposed to just foam at the mouth and regurgitate and spew things that cam from others and that may not actually be factual . . . Your attitude clearly makes you a non-credible source of information - objectivity went out the window a LONG time ago in your camp!

Have a few asterisks on me. Surely you are running low after that tantrum...
**************************************************

[Chris F]

	Quote: Originally Posted by tadawson
	To make it sound like XPS is the only one with problems really makes you sound like a total dips**t . . . - Tim

Save the offensive personal stuff for RCG Tim. It is out of place here.

[XJet]

Well it looks as if the SHIrT is about to hit the FANatic pretty shortly.

Official complaints have been filed with authorities in Europe and the USA in respect to the unsubstantiated claims being made by XPS/Graupner in respect to the XPS system.

It seems that JD will have to front up with some real evidence (and "I know it works" won't cut it) to prove his claims.

I notice also that there's been a significant increase in "unexplained" failures of XPS over at the XPS support forum on RCG. These are still being dismissed as due to faulty power systems, etc -- but when some folks have found that swapping out XPS and installing Spektrum or FASST causes the problems to go away -- well what does that tell you?

I still really can't understand why JD doesn't switch to an alternative tactic: tell the truth, admit the weaknesses, fix them, sell tons of product, make a fortune.

As it is, every time he's caught out (with increasing frequency) his credibility and the reputation of the product takes another dive.

Now he's claiming there have been "a million successful flights" with XPS.

How the hell does he know that?

Just more hype.

Sigh... such an opportunity shattered all to hell by a massive ego.

[KrisW]

	Quote: Originally Posted by XJet
	Well it looks as if the SHIrT is about to hit the FANatic pretty shortly. Official complaints have been filed with authorities in Europe and the USA in respect to the unsubstantiated claims being made by XPS/Graupner in respect to the XPS system. It seems that JD will have to front up with some real evidence (and "I know it works" won't cut it) to prove his claims. I notice also that there's been a significant increase in "unexplained" failures of XPS over at the XPS support forum on RCG. These are still being dismissed as due to faulty power systems, etc -- but when some folks have found that swapping out XPS and installing Spektrum or FASST causes the problems to go away -- well what does that tell you? I still really can't understand why JD doesn't switch to an alternative tactic: tell the truth, admit the weaknesses, fix them, sell tons of product, make a fortune. As it is, every time he's caught out (with increasing frequency) his credibility and the reputation of the product takes another dive. Now he's claiming there have been "a million successful flights" with XPS. How the hell does he know that? Just more hype. Sigh... such an opportunity shattered all to hell by a massive ego.

That's okay, Xjet. . don;t feel badly. . these things happen in the Hobby. This too, shall pass, and we will be the better for it. . now SMILE and go have a brewskie. . you sound like you could use one. .

[easytiger]

	Quote: Originally Posted by tadawson
	Yes, I see all the facts . . . and XJet does *NOT* have a lock on facts - just some strong opinions. Oh, and I guess that all the Futaba and Spektrum failures out there aren't happening either, at least not in your world? Damn shame that Futaba stuff can't take something as simple as the levels of heat at a lot of southern flying sites. To make it sound like XPS is the only one with problems really makes you sound like a total dips**t . . . My difference is I choose to both *look at* and *evaluate* the evidence, as opposed to just foam at the mouth and regurgitate and spew things that cam from others and that may not actually be factual . . . Your attitude clearly makes you a non-credible source of information - objectivity went out the window a LONG time ago in your camp! - Tim

Why is it that the fanboys always say "but Futaba and Spektrum have problems TOOOOOO!"?

That's like kids...they say "but SHE gets to do it, why don't I get to do it TOOOOOOO?"

Try that on a judge..."But judge...EVERYBODY was speeding! Why can't I speed TOOOOO? It's NOT FAIR!"

As if what Futaba or Spektrum were doing has anything whatsoever to do with XPS.

Either you get it or you do not...XPS has built in limitations that put it in a different category from F or S. Apples and oranges. One is suitable and safe for flying in model aircraft. The other, XPS, is not. It has endemic design flaws because it uses unsuitable parts. Futaba tried out the Xbee thing long before Jim Drew had the idea, and rejected as being unsuitable. If there really WAS such a simple solution as taking cheapo wireless router chips and putting them in a case, don't you think Fatooba or Japan Radio would have done it? Or are they just so stupid, and Jim so clever? Or, maybe, they are responsible companies with actual real live college degrees, and enough money to be worth suing, as opposed to the piker Jim Drew, who ain't really got a pot to spit in?

Hey, can outrant you any day of the week. And I don't even need asterisks. You're outnumbered, one to one! Meet you on the field of honor, tomorrow morning. Pointed barbs at twenty paces.
IF YOU DARE.


Xjet...let it go. It's a big joke already. You know, and I know, and most of the world knows, that anything that comes out of Jim Drew's mouth is suspect, be it his name, his claims for his system, or even "pass the ketchup". If Jim Drew said "pass the ketchup", I would ask for independent verification before I wasted the energy to actually pass the ketchup. He probably really wants the mustard, but just cannot tell the truth, he's just unaccustomed to it.

Tdawsons, ChrisFtestpilots, these people are the final holdouts...the Walloons defending the Brandenburg Gate as Berlin crumbles around them. They backed the wrong horse and can't surrender. They can stack up those mythical tens of thousands of XPS receivers into little bunkers and ramparts and keep sniping away as the ring slowly tightens around them, but sooner or later, they will all fall. Or get hit by falling aircraft. And you know what they will say, just like the Holocaust Deniers? "We VOULD have von iff only ze politicians did not ztab us in ze back!"

[Woketman]

ET did not take this argument to its logical conclusion.

Yes, Futaba & Spektrum had/have issues (low voltage resets, GUID issue, temp. issue), but generally, these are things that we can manage. I can be certain that my power source is up to snuff. I can wait for GUID fix or use the higher end systems that were unaffected. I can put a towel over my plane and keep it shaded and not put my RX in a green house.

What I CAN NOT DO is figure out how to majically get the reciever to tell the servos to move to exactly where I want them. THAT is what I want a 2.4 GHz system to do. Kiwi proved, beyond a reasonable doubt, that Futaba & Spektrum are far more reliable in realistic environments than XPS! I can put up with the small foibles, I cannot design my own reliable 2.4GHz link.

THAT is why we need Futaba or Spektrum and we definitely DO NOT need XPS (unless you enjoy crashing high $$$ turbine aircraft, I do not)!

[kevinelp]

Hmmm, this is starting to sound a little too witch-hunt like for my liking. Okay, JD probably is a witch, but that should not kill rational debate.

Yes, spektrum and futaba are a better option with a high degree of confidence. I own and love my DX-7.

However, Kiwi's test was a limited scenario, I'd like to see other scenarios - such as weak TX signals (at various strengths), combined with interference of various types (narrow band, wide band, strong, weak), we should be able to infer RX sensitivity, maybe processing gain, etc, etc. Though I have to admit that I'm more curious about the relative merits of spektrum versus futaba, and acknowledge such tests are hard to do without serious gear in the lab.

XPS crashes actually may have little to do with lack of hop, it could be ****ty QA, or ****ty firmware that crashes (pun intended ), or lack of diversity, or a combination of all of the above.

Assuming the witch is burnt (do I smell smoke...), it should not mean we stop taking a critical view of what we understand thus far, and continue independently testing the bits of kits we rely on when we can.

Anyway, dons flame proof suit - I'm not a witch, really.....

cheers,

- Kevin

[easytiger]

"Hmmm, this is starting to sound a little too witch-hunt like for my liking. Okay, JD probably is a witch, but that should not kill rational debate."

Rational debate ended a long time ago. Actually, rational debate cannot include one party lying through their teeth.

You can rationalize it any way you want, but that thing don't hop. And that thing don't WORK. It crashes planes, simple as that. Kiwi's test may not have been approved by Underwriter's Laboratory, but it's pretty simple stuff...if you turn another device on, the XPS is supposed to move to a different frequency. Pretty simple. But it don't. It sits there until it's swamped. It's a dead issue. An ex-parrot. It does not hop, and it does not come with wafers.

Look...no matter how you slice it, it's still baloney.

[Reckless Loony]

	Quote: Originally Posted by KrisW
	So, are we supposed to "understand" his condition, or put him out of business?

I was merely looking for an explation as to the cause for the continous stream of BS coming from JD especially since some of the BS is over trivial matters. Anyway I firmly believe he is a pathological liar and therefore you can expect the flow of BS to be never ending.

	Quote: Originally Posted by Kiwi
	As for the system being flown at the Nall. I think JD had an electric jet that he flew, there where some flying wings that were all up together that were XPS setups but I did not see anything else.

This is what JD claims

	Quote:
	The interesting thing was with 600 pilots registered there was a maximum of 21 radios in the 72Mhz impound. That left a minimum of 579 radios out in the crowd capable of being switched on. In the seven days I was at the field there was not one single shoot down. While I cannot attest to the exact numbers I would have to say that Spektrum looked to be the leader in units on the flight line and FASST running hard behind. Apart from the four XPS units I did not see any others but there could well have been. As a portion of market share I would say XPS was barely visible on the graph.

According to polls on various forums Spektrum/JR hold about 70 to 80% of the 2.4Ghz market and XPS is a very small player.

At my field the DX7 is very popular, no XPS and a couple of Futaba FASST high end radios. The only reason why FASST isn’t popular in Australia is because only just very recently has the Futaba 7C 2.4Ghz radio become available in Australia due to the exclusive Futaba importer/wholesaler being useless.

	Quote: Originally Posted by XJet
	I'm sure JD has designed frequency agility into XPS, the problem is that it's like being given a raincoat on a sunny day -- it only works when it's not needed.

Actually the only hopping XPS does is during the power up phase if needed. However even this doesn’t always appear to be reliable especially if a 2.4Ghz video camera is nearby according to Hcopter. XPS didn’t move away from the video camera frequency until the third power up.

	Quote: Originally Posted by ricoalonso
	It looks like XPS has released or at least stated the parameters/conditions to make their unit perform the illusive hop. Here's what JD mention in his RCG post at http://www.rcgroups.com/forums/showthread.php?t=869306 post #15

Its been deleted.

As everybody knows XPS uses the Digi Xbeepro 2.4Ghz modules. XPS operation is completely dependant on the capabilities of these modules. I have posted the user manual for these modules earlier in this thread and here it is again.

http://ftp1.digi.com/support/documen...5.4_v1.xAx.pdf

Those that believe in this statement

“The existing hopping requires the noise floor within +/-15MHz of the frequency to slowly rise inside of 512 frames (about 11 seconds)”

Could you please inform myself and fellow forum members by what means can the Xbeepro modules detect and measure a rising noise floor 15Mhz away? Please specify page number of the manual or even the AT command(s) that allows the Xbeepro module to do this.

As I mentioned before the Xbeepro modules are nothing more than transceivers just like a walkie-talkie or CB radio and the Xbeepro modules operate in the same way as a walkie-talkie or CB radio but instead of analog voice transmissions its digital data transmissions.