Kiwi's XPS test results are up.

[KrisW]

	Quote: Originally Posted by XJet
	But I think JD said just a while ago that he's still in the paintball business. And it's not anyone's job to put anyone out of business -- just redress the balance of hype and deception versus reality. If it weren't for the FBs, this would be a simple task -- JD would say one thing, others (and Kiwi's tests) would say another. People could review both and make their own minds up. Unfortunately, the FBs continue to praise Lord JD and keep alleging that the naysayers are simply on the payroll of Futaba or JR and have some kind of personal agenda against their exalted one. Whenever anyone asks a legitimate question and an objective response, that response usually gets deleted by JD or shouted down by the FBs (chances are that the response I linked to, which simply read " No, they're about the best independent testing we've got at the moment" will have already been deleted by the time you read this). That's why the "naysayers" maintain a presence -- to establish the balance necessary to keep otherwise uninformed people aware of the facts.

Yup, they've been deleted.

Absolutely amazing how touchy this guys trigger finger is.

[spoiler]

	Quote: Originally Posted by jonkoppisch
	& the results are (after the responses are all deleted)....

That response may be totally expected, but it is also totally disengenuous. The question relates not to the technology behind/inside the system, but whether that technology actually does what the manufacturer says it does. This is obvious to all except XPS it would appear and the kind of response that should ring alarm bells with any customer even vaguey concerned with safety and getting what he paid for...

[easytiger]

	Quote: Originally Posted by KrisW
	Yup, they've been deleted. Absolutely amazing how touchy this guys trigger finger is.

Except...I made a post HERE last night and it sure looks like it was deleted by Flying Giants.
Which is now, as I understand it, just another subsidiary of RCgroups, which is in the pay of XPS...

[Kiwi]

Easy,

I just sent you a pager but in case you miss it where was the post that was deleted?? I was on here last night and I see no deleted posts.

If we delete a posts it leaves a yellow bar to show where it was pulled from. I see nothing here that was yanked.

[XJet]

	Quote: Originally Posted by spoiler
	That response may be totally expected, but it is also totally disengenuous.

I see now that JD is claiming (in light of threatened investigation by European authorities) that he never said the frequency agility of XPS was designed to avoid interfering signals -- no, it was only ever designed to improve the range of the system.

Well he's been caught out on that one too. Here are quotes from postings he made on RCU back in 2006:

We are the ONLY 2.4GHz system that has the ability to monitor the available frequencies in the 2.4GHz range and change as necessary, in real time. This means that the plane as well as the transmitter can make the change occur. If you flew your plane over a school with a huge 14dbi external 802.xx antenna, that would likely be cause for switching to a new frequency (away from whatever channel that 802.xx was on)

In the same post he also claimed:
"Even 2.4GHz cameras are not a problem as we can move around their frequency, even with huge drift that occurs in the cheap overseas versions. Our system is extremely well thought out for safety reasons"

And perhaps the most damning claim, also on RCU in 2006:
"If there was a burst at a particular frequency or range, we would just hop to something that wasn't an issue. Now, if you had some other competing 2.4GHz radio... you would be in trouble. "

The guy is BSing and he's been show so many times to have lied that I really wonder if his FBs are the kind of stuff that would interest a university specializing in human psychology. Some PhD student could write a wonderful thesis on this -- it's absolutely unbelievable that so many people can ignore the facts even when they're presented to them on a plate.

[tadawson]

I dunno - seems to me that avoiding interfering signals is a pretty damn fine way to increase range . . . . so I think the statements overlap, if folks can just take the "attitude blinders" off and look at the statement clearly . . . .

- Tim

[Pale Rider]

	Quote: Originally Posted by tadawson
	I dunno - seems to me that avoiding interfering signals is a pretty damn fine way to increase range . . . . so I think the statements overlap, if folks can just take the "attitude blinders" off and look at the statement clearly . . . . - Tim

Your kidding right ?

[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

	Quote:
	Kiwi's test will never be able to reproduce it. The existing hopping requires the noise floor within +/-15MHz of the frequency to slowly rise inside of 512 frames (about 11 seconds). Remember, this is a predicitive hop designed to increase range. It was never designed to fix a saturation issue as that does not occur in the real world without all of the band being wiped out. People have already reported using the XDP to monitor their flight, taking off and one channel and landing on another. This is how it is possible. Incidentally, the AirHorn devices being used in Kiwi's test are not FCC certified. I contacted the supplier and they could not provide a FCC ID either. The noise (band to band splatter, increasing the noise floor) is pretty severe. However, just moving our receiver a few feet away foils that bench test. The bench test failure requires the receiver's front-end to be swamped, which is why it stops working. The additional hop code is going to just foil the bench test by moving to another frequency. This will likely never be used ever in the real world, but it should silence the nay-sayers. This is a FIRMWARE only upgrade. The XBEE Pro hardware and our existing firmware we program on the XBEE module is quite capable of frequency hopping full time, and according to the FCC is allowed as a DSS device (much like what Futaba does with the FASST system). I am not a fan of full time frequency hopping as it typically reduces the overall range, since you are hopping through congestion. Fortunately the XBEE hardware is very sensitive, so that will help make up for it in Europe, where full time hopping will be required August 1st. This upgrade is certainly not required, but it does add some real features like the telemetry package, multiple servo outputs modes, voltage monitor, etc.

One thing I am confused is the statement above regarding the additional code. If the original version of XPS already does the hopping... why need the additional code to move to another frequency? Isn't hopping the same as moving to another frequency?

^R^

[XJet]

I'm pretty sure that XPS will hop under those parameters -- but that's kind of like having a raincoat on a sunny day -- absolutely useless.

Interference doesn't slowly increase over an 11-second period in the "real world" so it's useless as a method of avoiding the kind of interference you're *actually* going to encounter when flying a model.

As I've always said -- XPS has no useful frequency agility and JD has just confirmed that with those parameters.

[tadawson]

	Quote: Originally Posted by Pale Rider
	Your kidding right ?

Not in the least. I see a lot of things that are true, and a lot more that are simply nitpicking due to different interpretation of the definition of words. I have no vested interest in any 2.4 system (Frankly have yet to see the need, but am watching) so am trying to look at things in an objective, non emotionally clouded way, which is something I can't say is true about a lot of the folks posting on this topic.

And yes, avoiding conflicting signals is a very good way to maximize range . . . no grey area there at all . . .

- Tim

[Pale Rider]

	Quote: Originally Posted by tadawson
	And yes, avoiding conflicting signals is a very good way to maximize range . . . no grey area there at all . . . - Tim

Yes in that regard I agree with you--Im a happy DSM user but am still interested in the discussion..
It does seem JD does a LOT of double-talking so Im very skeptical of anything he says at this point.

[XJet]

	Quote: Originally Posted by tadawson
	And yes, avoiding conflicting signals is a very good way to maximize range . . . no grey area there at all . . .

But the problem is that (as the tests prove) it *doesn't* maximize range under the conditions that count -- strong on-channel interference.

It only optimizes range at extreme distance where the increasing distance produces that slow 11-second ramp-up in the background noise that JD refers to as the trigger for frequency hopping.

Quite frankly, I don't know why anyone would care if their 2.4GHz system will operate over 5 miles rather than 4 miles when the model became too small to see at 1.5 miles anyway.

The *real* reason people want frequency agility is so that they don't get shot down by a sudden burst of noise on the system's operating frequency.

JD has very clearly told us (now) that his hopping doesn't address the interference issue, it's only been there for range-enhancement.

But... strangely enough, up to this point he's sold it on the premise that it will hop to avoid interference -- such as flying over a strong WiFi transmitter.

Be honest, you must see that he's rapidly backpedaling to avoid getting into big trouble in Europe where they actually issue very stiff fines if you make false claims about your product.