Independent tests prove lack of frequency hopping with XPS

[jonkoppisch]

This is interesting... Here we have a video and the other, someone telling what it does (no test or anything, just saying it does). Which one is false?

Independent tests prove lack of frequency hopping with XPS

	Quote: Originally Posted by Kiwi
	... Just to reiterate so the facts don't get lost in the jungle of comments here..... NOTE!!! Exact same conditions. The noise was not ever dumped in a solid burst on any one channel. If you look at the scanner you can see the spread was wide enough that as the noise transitioned across the specktrum each channel was slowly exposed. It was never hit with a solid burst such as a video transmitter etc would do. XPS stopped functioning every time....

http://www.rcgroups.com/forums/showt...90#post8941390

	Quote:
	skubacb Again it is a twisting of the facts. The jumping is preemptive. IE it looks ahead to see what channels are clear and IF the noise floor is increasing it WILL jump to a new channel as necessary. What you are getting is a twisting of the facts. The system works exactly as we were told it would. I accept what Jim has told us about the system because what he has told us is what the system does.

[jonkoppisch]

1 more thought. Since xps users and jd put a large emphasis on the test done at the Boeing plant (not verified etc) and are using it for justifying that xps does hop. Someone should contact the Boeing facility to see if the test is valid. Since their using Boeing to justify it, then they're bringing in the facility. You can't say, the boeing engineers tested xps and it hopped but you can't check or ask about it... You just have to take our word. That's not a credible source... Of course, that's the same thing that xps says.. It hops, take my word for it....

[wrightme]

Hardly anyone except you and others with your vendettas are even talking about that test. Obsession is an unhealthy pursuit.

	Quote: Originally Posted by jonkoppisch
	1 more thought. Since xps users and jd put a large emphasis on the test done at the Boeing plant (not verified etc) and are using it for justifying that xps does hop. Someone should contact the Boeing facility to see if the test is valid. Since their using Boeing to justify it, then they're bringing in the facility. You can't say, the boeing engineers tested xps and it hopped but you can't check or ask about it... You just have to take our word. That's not a credible source... Of course, that's the same thing that xps says.. It hops, take my word for it....

[jonkoppisch]

Oh Please.. FB's bring it up all of the time to justify the hop..

Obviously, that's where it came from..

[Woketman]

Instead of using the word "Boeing", why not just substitute "Fantasyland" from now on when describing that test? It should result in the very same credibility!!!

[GBR2]

The main problem with the hopping issue isn't if it hops (which it probably does but only under those super specific XPS mystery conditions) but whether it hops in a useful manner to provide frequency redundancy. Spectrum does that through using 2 channels and FASST by hopping all the time. I've talked to numerous members in our club and given them this JD quote:

“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.”

They all assumed that if interfering noise were to show up on the "channel" in use and there were clearer ones, that the system would just move to it. That is the kind of frequency redundancy hopping that people expected based on all the marketing talk JD did about the system. The videos by Tychoc and Kiwi show that this type of frequency redundancy hopping is not currently present in XPS hardware. Whether it hops under those very specific XPS noise hopping conditions really is immaterial as it isn't very useful.

I know one of the main reasons I purchased a small amount of equipment early on was I assumed it had the type of frequency redundancy that the JD marketing campaign was promoting. I also liked the fact that it was made in the US but in the end I feel I was basically deceived about an important aspect of any 2.4 system I would consider purchasing. Currently I'm using Spektrum equipment.

[Kiwi]

I often wonder if the continued denial of what I found and what others have shown as fact is in fact an attempt to have this thread locked down so it disappears.

It makes sense if you keep nagging at the denial syndrome people get bored or sick of it and close it.

Well that is not going to happen as I'm waiting for the Mk2 version to be released from XPS so we can do some field testing on it as well.

Just for the record I have three other brands in the gunsight and pre orders are placed for a sample. They too will be put through the same sequence of tests.

In the time being if any of you are interested in delving into the 2.4Ghz quagmire dont forget the guys who helped us do this.

www.nutsaboutnets.com

www.metageek.com

Take a look at the websites and see what new data they keep coming up with.

[Gordito Volador]

	Quote: Originally Posted by capgains
	Yep this is a whole new level of obsession.

Absolutely correct! The Fan Boys get their marching orders and here they come to re-educate the unclean. Just watched another XPS at our field lock out on a big gasser doing 3D. Still waiting for the post mortem, but I'll bet in the end the grass was wet.

Many thanks to Kiwi for his efforts to visually document this issue!

Regards, Bill

[adjonym]

	Quote: Originally Posted by skubacb
	As JD has proven himself? <img> humour, humour, humour. This besides being funny may even be delusional. I don't claim to have read everything he has said but this is certainly not correct. One last time; for the intellectually challenged: The XPS system will only hop under specific conditions. Apparently, Kiwi's 'test' did NOT provide those conditions.

Once again, for the intellectually challanged: Extreme Power System is required by law to provide the evidence needed to back up their claims in marketing.
Now, point me to the evidence XPS has provided about their frequency switching technology claims.
And again, for the intellectually challenged ones, that means that the burden of proof lies with the manufacturer, not with the customers, or possible customers. Those laws are in place to protect both customers AND possible customers, so that they can base their purchase on the features a product actually have, not what the manufacturer CLAIMS that they have.

Now, if all comanies acted as Extreme Power Systems, you'd have cancer medicine with 100% success rate, all it would take would be a 1-800 number and a credit card. You'd have cars with 10000mpg rating, just with the addition of the X capacitor, and so on and on. These might be bad examples, since they are easy to spot, and turn away as bs, but you get the idea.

I think this is the base of all this fuzz. We, as consumers should always act upon company's that refuses to follow those laws, and even base their marketing upon it(JD claims he won't provide proof since it helps sales). Those laws are there to keep scammers out of the loop.

No matter how you turn things around, the fact still remains; Extreme Power Systems are breaking the consumers law, and continue to do so well aware of the fact that they are indeed breaking those laws.

[wrightme]

	Quote: Originally Posted by Gordito Volador
	Absolutely correct! The Fan Boys get their marching orders and here they come to re-educate the unclean. Just watched another XPS at our field lock out on a big gasser doing 3D. Still waiting for the post mortem, but I'll bet in the end the grass was wet. Many thanks to Kiwi for his efforts to visually document this issue! Regards, Bill

"Marching Orders?" That is rich.

Any of you who believe that all XPS users are at JD's beck and call are fooling yourselves.

[zoomer260]

	Quote: Originally Posted by adjonym
	Once again, for the intellectually challanged: Extreme Power System is required by law to provide the evidence needed to back up their claims in marketing. Now, point me to the evidence XPS has provided about their frequency switching technology claims. And again, for the intellectually challenged ones, that means that the burden of proof lies with the manufacturer, not with the customers, or possible customers. Those laws are in place to protect both customers AND possible customers, so that they can base their purchase on the features a product actually have, not what the manufacturer CLAIMS that they have. Now, if all comanies acted as Extreme Power Systems, you'd have cancer medicine with 100% success rate, all it would take would be a 1-800 number and a credit card. You'd have cars with 10000mpg rating, just with the addition of the X capacitor, and so on and on. These might be bad examples, since they are easy to spot, and turn away as bs, but you get the idea. I think this is the base of all this fuzz. We, as consumers should always act upon company's that refuses to follow those laws, and even base their marketing upon it(JD claims he won't provide proof since it helps sales). Those laws are there to keep scammers out of the loop. No matter how you turn things around, the fact still remains; Extreme Power Systems are breaking the consumers law, and continue to do so well aware of the fact that they are indeed breaking those laws.

My bad. I thought for a minute that you were saying JD has proven the "hop". Just the fact he won't show it hopping "in real world testing" was enough evidence for me that it would not. Kiwi did a lot of work attempting to get it to and the results are in.

[tadawson]

	Quote:
	Nothing was saturated,

That has not, and cannot be proven with any of the test gear in that video. The saturation being discussed here is RX front end - not band, which cannot be seen on any external test equipment - you have to monitor the internals of the RX to see it. The net effect of an RX front end saturation would be that it would desensitize the RX across the band, and render it's ability to scan moot. Not gonna be able to negotiate much of anything that way. Not to mention that the noise source was also close to the TX, which also has a receiver in it, used to negotiate changes. How much might the close range noise source have affected that? Unknown at this point . . . . A more sensitive RX will typically encounter this type of problem at lower levels than a lesser sensitive unit, so it is not impossible that this test simply sat in that window.

This is why I continue to suggest that this test should have been run (or be rerun) at realistic signal levels to what would be seen in flight. With an interference source and TX unit sitting basically right on top of the RX, the chance of this happening is far to great to ignore. The apparent success of other systems under these conditions is basically meaningless, since it may simply mean that they have less sensitive receivers in the first place (as well as other possibilities).

So, for me, it comes down to this:

ONLY TESTS DONE AT IN-FLIGHT SIGNAL LEVELS HAVE ANY CREDIBILITY. THE REST ARE FAR TOO PRONE TO OTHER ISSUES TO BE DEFINITIVE IN THEIR CONCLUSIONS.

And, as stated before, band saturation and RX front end saturation have very little if anything in common, other than the word "saturation". It appears that there may be a number of folks here who do not understand those definitions, as evidenced by claims like my beginning quote, where there was no possible way of knowing that . . .

- Tim