Kiwi's XPS test results are up.

[jonkoppisch]

And another..

	Quote: Originally Posted by Phoinix
	I am happy to tell that i have just sold mine to a modeler happy with experimenting. Bought the equipment for 450€ and sold it for 175€. The price went as high as i could. Nobody in europe trusts XPS any more, the word is out. However, I had two occurances with IFS. First was practicing hover autorotation. The system switched itself off, green light all the way, no servo movement. 15 seconds later it all began to work by it self. Another was sport flying. Pulling out of a loop, signal lost. Helicopter crashed and rolled, removing the battery out of it's place and disconnected everything so no data there. I checked every single soldering joint, tested all electronic components down to it's guts. RX power supply was in both cases different and working perfectly. I have eagle tree wired around all my helis big time. If it was just a small spark on the RX system i would know about it, and there wasn't any. I'm not saying it's crap. I had a lot more trouble with PCM, and it it an upgrade. But, if I can't trust my 3000€ worth scale helicopters to my RX/TX equipment, i won't use it.

http://www.rcgroups.com/forums/showp...&postcount=240


Is xps better than 72???

Well, you may not get shot down if someone else turns on but the chances are extremely high according to jd if you use switches, regs, li ions etc etc etc...

http://www.rcgroups.com/forums/showp...8&postcount=72

	Quote: Originally Posted by JimDrew
	I would say that we get no fewer than one customer a week reporting that a switch gave them a problem with their setup. With dozens and dozens of cases reported now since we have started shipping this product, it only makes sense to make people aware that switches are in fact a problem.

Surprisingly switches etc don't seem to be a problem for fasst and spektrum....

[Raypadro]

	Quote: Originally Posted by gregw
	It's been a few months since the promised "hopping" video that JD said he was going to produce, but so far, nothing has been shown. There is also no indication as to when the "new" firmware will be released. So, I've decided not to wait any longer. I'm moving away from XPS and have just purchased a Futaba TM-7/R607FS FASST combo for my 9CHP. I haven't had any problems with XPS at all, but due to my lack of confidence, XPS will now be used only for foamies and park flyers. Thanks to Kiwi for showing in a very definite and repeatable fashion, that Spektrum and FASST will fly through the interference that will cause XPS to freeze/fail-safe.

Good move...

[jonkoppisch]

Just put another 1st flight on a new comp arf Flash Jet (same as I had and same setup as the first with xps).... Fasst 2, xps 0...

PS, this jet used many of the same components that were in the first jet.. Servos, leads, turbine (after a $1500+ repair), etc..

[Gordito Volador]

Based on all of the research and testing that's been done I have come to the conclusion that XPS is ok; if you don't ues switches, don't range check over wet grass, don't expect it to hop when interference is present, don't mount the Rx near any wiring in the plane, don't use it in Italy, and most importantly don't expect to be able to call anyone on the phone for tech support.

[Toumal]

	Quote: Originally Posted by jonkoppisch
	Yep, he said it again. No mistake. xps does NOT hop if you encounter interference unless it shows up VERY slowly.... Quote: Originally Posted by JD As we have stated previously, a sudden increase in the noise floor (or frequency in use) will deliberately not change frequencies. This was not by accident as in the real world, if the frequency in use becomes fully saturated, the entire band is also saturated.

JDs statement is wrong on so many levels. However, actual knowledge probably doesn't matter in the discussion over at RCG anymore. I doubt that me or someone else having studied this stuff and holding an engineer degree in electronics makes any difference. It's also very convenient that the thread in which this bit was posted is now locked.

The thing is that XPS probably could be changed to facilitate continuous frequency hopping, but would you want to trust the technical skills of someone who doesn't even know (or deliberately ignores) the radiation characteristics of a ground plane antenna?

I wouldn't go so far to say that switches are no problem for Futaba (I take it we all know of the voltage and temperature issues), but these are issues that can be avoided. Interference popping up on your channel like someone plugging in his wireless router is not something you can prevent from happening.

The fact of the matter is that hopping away from the interference is what needs to be done, and XPS/IFS obviously isn't doing it in a reliable fashion. I've heard many first-hand reports of problems at the field and all I see from JD so far is excuses, misleading statements and outright false information. I just hope that people considering to buy a 2.4 GHz system do some research before buying something. Of course I know that die-hard brand loyalists who always buy Graupner will also buy IFS no matter what we say.

What astonishes me is the way the press keeps silent about this. Claims such as the "spherical radiation panntern" are easily debunked. It is actually the responsibility of RC magazines and websites to shed light on this whole affair. If nothing else, the untrue claims should be examined and exposed. Where are the critical reviews?


(BTW, just in case anyone feels like sueing for my statement here: My war chest is filled and I'm not impressed by C&D threat letters, so... suit yourself)

[XJet]

Toumal, some of us have been trying to educate the world to the utter garbage that Jim Drew has been spouting ever since the system was announced.

Fortunately, it would appear that the truth is finally sinking in and from what I've heard, XPS has such a small percentage of the market in the USA that it hardly registers.

I suspect that Graupner are also really regretting getting into bed with a snake-oil salesman like JD. It's a shame they didn't research both the man and his products before they signed up to XPS.

[Toumal]

	Quote: Originally Posted by XJet
	Fortunately, it would appear that the truth is finally sinking in

Never underestimate the power of repeating the same phony statements over and over:

See http://www.graupner-ifs-system.de/en...achhandel.html

	Quote:
	The IFS course was highly informative, with a strong practical bias. We have all read the negative reports in many Internet forums, but in our experience the information is generally subjective and often simply incorrect. We have found that many of our customers now ignore information on the Internet, as it is often “not worth the current used to supply it” (customer quote)

	Quote:
	To anyone who consults the Internet forums I would offer this advice: it’s far better to allow competent people with real expertise to show you the way, than to try to pick your way through the Internet morass.

That kinda looks to me as if Graupner is going all the way with this.

[XJet]

It would seem that Graupner have done *no* real tests of their own, despite what is claimed on this page


Statements such as:

	Quote:
	The IFS uses all of the available frequencies in the ISM band through an advanced proprietary predictive frequency hopping technique

Is utterly wrong and has already been debunked.

Leaving aside the issue of Kiwi's tests which prove no "predictive hopping", the XBeePro modules operate only on 12 channels, each with a 1.5MHz utilization within a 5MHz allocation. That amounts to a mere 18MHz utilization of a band that is 80MHz wide. Hardly "all of the available frequencies".

Then there's this:

	Quote:
	The Graupner IFS system features a 16-bit system providing 65,536 steps to the servo outputs. The IFS system features ample reserves of bandwidth, and future developments could allow the system to carry live video and audio transmissions!

Utter BS!

For a start, no currently available transmitter will deliver 16-bit outputs to the servos.

Secondly, there is nowhere near enough bandwidth in the XBeePro modules to cope with live video. The actual throughput of the modules is about 130Kbps (the raw RF is 250Kbps but network and packeting overhead consumes quite a bit of that). I have yet to see any way to reasonably encode the kind of "live video" you'd need for a model into such a narrow amount of bandwidth without totally monopolizing the timeline to the point that the CSMA system would become an issue for other users.

No, IFS has simply swallowed the JD hype hook, line and sinker.

From what I've heard, Graupner are facing an increasing number of complaints and have started refunding money on many occasions. There's also a complaint under Sweden's consumer protection laws. New instances of XPS/IFS causing unexplained crashes in Europe are popping up with increasing regularity.

I suspect that Graupner and JD are engaged in some rather heated discussions right now but neither party would likely be prepared to admit it for obvious reasons.

[sweetpea]

	Quote: Originally Posted by Toumal
	What astonishes me is the way the press keeps silent about this. Claims such as the "spherical radiation panntern" are easily debunked. It is actually the responsibility of RC magazines and websites to shed light on this whole affair. If nothing else, the untrue claims should be examined and exposed. Where are the critical reviews?

Sorry but when was the last time you actually read a review by any R/C rag?

None of them debunk or tell you not to buy something. Not good business for them to do so as that would pull advertising from that company and most likely other companies. It would have to be a rag that didn't rely on R/C advertising to keep its profit margin. I put no faith in any review I see from an R/C rag.

[Woketman]

Well, I agree with Sweetpea. But in this case I don't think JD is spending any $$$ on advertising in any magazines. So I would like to see a mag do an honest review of XPS. But I won't hold my breath.

[klhoard]

R/C Report magazine out of Huntsville, AL always "Tells it like it is". . . .

[Woketman]

Have they reviewed XPS? If not, can anyone who knows the staff ask them to?

[XJet]

	Quote: Originally Posted by sweetpea
	None of them debunk or tell you not to buy something. Not good business for them to do so as that would pull advertising from that company and most likely other companies. It would have to be a rag that didn't rely on R/C advertising to keep its profit margin. I put no faith in any review I see from an R/C rag.

That's why I launched RC Model Reviews which is now getting very good traffic.

Interestingly enough, advertisers are a little slow in coming out of the woodwork -- perhaps because when they ask if they can advertise alongside a review of their product I tell them "no they can't".

Likewise I've had a lot of manufacturers offer me product "for review" but I've told them that I only review stuff I've bought and paid for myself so that there's no question about the integrity and objectivity of the reviews.

Of course this leaves me reliant on donations and generic advertising in order to fund the purchase of review products and to run the site -- which isn't exactly making life easy and certainly not covering the costs right now.

But the RC public deserve some reality rather than advertorial reviews

[Simpleton]

	Quote: Originally Posted by Woketman
	Have they reviewed XPS? If not, can anyone who knows the staff ask them to?

Would they have the gear to do an expose' style review, or just hook it and say if it worked or not? If they hooked it up and it worked fine for them, it might lend credibility to XPS that was unwarranted. I don't remember seeing many "radio reviews" in the past that looked into the inner working nuts and bolts, just the features.

[Kiwi]

The problem is guys there's no real benefit to anyone to go and spend a wad of dollars to test the system unless it becomes a consumer or legal issue. Then, and only then will some one with the budget and equipment required do a thorough totally indisputable test do so.

But then again I am sure JD would find a way to rebuff even the most independent and thorough tests anyway. Thats not banging on him either, its his business so he is going to try and defend it to the death.

I get the feeling that the European consumer complaint may have the best result as far as functionality to see if it does what is advertised. Apart from that no matter what we do as individuals we will never get 100% acceptance from the doubters. Thats human nature.