Independent tests prove lack of frequency hopping with XPS

[exeter_acres]

Your thread would have held much more water if you started it with your proof versus making claims with no proof (YET) to back it up......and saying it will come later.......

Might have gone differently

[bodywerks]

	Quote:
	Sueing seems to be the favourite pastime over there in the US.

Sad but true...

[madmax]

XJet, we invite all modelers who have the knowledge and experience in testing equipment to post their findings here, so long as it is done respectfully. Send 'em over.

[bodywerks]

I for one lost a little faith in X-link when they added the makeshift antenna to the module. But I know people that are happy with them, and I am happy with my Spektrum. I will let this thread go...

[gmilo]

I for one lost faith in X-link when JD claimed that the 1st delay in introduction was due to a delay in receiving plastic receiver enclosures from the Asia supplier that 'were in transit'.....this transit time turned out to be about 6 months. Just a bold face lie IMHO that I didn't appreciate as a reasonably intelligent consumer. When I go 2.4, it will be JR or Futaba, but not XPS

[sweetpea]

Funny. I'm happy that Xjet has taken the time to post his findings.....yet not post how the findings came about, who the testors were and how controlled the experiments were.

Again I'd like to see what the test entailed so that they can be put up against all 3 companies equally. I'd like to see what it takes to fail Spektrum on the 2 signals, how close they really are, what effect the floor noise has etc. I'd like to see the effects of the same thing on Futaba.

And I would not say I'm a "Fanboy" of XPS. I will say I'm a "Fanboy" of 2.4 They all have strengths and weakness's. All 3 of the companies have flat out lied in the advertising about "immune to intereference" I fly both Spektrum and XPS. I don't fly futaba because that would require me to buy a new radio.....My 10X isn't broken so why buy a new one?

Since I wasn't flying R/C back when PPM went to PCM I suspect the same type of false advertising happened then and planes were lost and continue to be lost and will be lost in the future as well.

And no one has disputed that XPS has found some problems with their system in the average joe's hands. Such is the life of electronics. Spektrum found the same thing out (battery voltage ring a bell). You cannot possibly test every situation that some moron will put your system through. No different than a car being recalled from Ford or Chevy. I guarntee Futaba will see the same thing once they start hitting the market hard.

As for the satellite rx's from XPS......they were stated from day one to be an option. I for one don't care what any of the 3 companies have to say about signal strength/path etc. 2.4 is a narrow beam on a narrow antenna. On a large plane too many things get in the way. Give me multiple antennas (similar to 72mhz which put the antenna the length of the fuse) so that the signal has a better chance of being recieved. I'll pay the extra money for the extra piece of mind. To me that's no different than using extra batteries or switches or dual RX's in 72mhz.

But the best part of all of this.............

I should not take the companies word on how their system should work......But I should take yours (or your independant testors) without any proof

Thanks for clearing that up for me.

[sweetpea]

	Quote: Originally Posted by madmax
	XJet, we invite all modelers who have the knowledge and experience in testing equipment to post their findings here, so long as it is done respectfully. Send 'em over.

Heck yes.........bring the data on.

I'm all for knowing exactly why something works or doesn't with the reasons behind it.

[jonkoppisch]

I wish that I had known about the 'exaggerations' before I purchased the xps system. One of the main reasons that I bought it was that it was promoted that it would jump to another channel if it encountered any interference. It sounds as if there are only 11? channels that it can switch to if the circumstances are just right. It worked for me.. Then it didn't...

[XJet]

	Quote: Originally Posted by sweetpea
	But the best part of all of this............. I should not take the companies word on how their system should work......But I should take yours (or your independant testors) without any proof Thanks for clearing that up for me.

But JD himself has has (when confronted with the truth) has admitted that XPS will not frequency hop when exposed to a sudden rise in the noise floor or strong interfering signal. So why question my findings when JD has confirmed them?

You're saying JD is right when he says it won't hop but when I say it won't hop, I'm not to be believed without proof?

Do you not get it.... JD said (direct quotes):

"The frequency hop requires a rise in the noise floor over a number of frames. A sudden saturation will reset the noise counter and not switch at all."

"If the noise becomes so high that it saturates the channel, the hopping counter is reset and the system will not switch"

So, even if I didn't provide proof (which I will), why would you question this? If JD says it's so, surely it *must* be so.

Why would he admit to a non-existent flaw in his own system?

The XPS won't reliably frequency hop when hit by sudden interference -- this much is beyond doubt, even JD admits it.

[XJet]

	Quote: Originally Posted by jonkoppisch
	I wish that I had known about the 'exaggerations' before I purchased the xps system. One of the main reasons that I bought it was that it was promoted that it would jump to another channel if it encountered any interference. It sounds as if there are only 11? channels that it can switch to if the circumstances are just right. It worked for me.. Then it didn't...

And that's *exactly* what I'd expect to see with this limitation in XPS.

So long as the frequency chosen by XPS is clean and remains that way, XPS will work just fine and dandy. It's only when something else decides to use a fair bit of that chunk of spectrum that you'll have problems -- and XPS will have no fallback capabilities, leaving you looking for a shovel.

Some folks will never have a problem - ever, others will never have a problem until "one day" when a new 2.4GHz gadget down the road decides to broadcast all over the top of you, or you decide to fly at another field where Futaba and Spektrum systems are working without problems but your XPS may not, due to the presence of powerful 2.4GHz transmissions that come and go on an XPS channel.

No worse than 72MHz -- but not as good as other options.

[3ddd]

Sueing seems to be the favourite pastime over there in the US.-----sweetpea you said what i intended to,great job by the way--and my only thing with the sue comment is the fact that anybody can sue for slander or anything they want to anymore,it was just a friendly word of caution that all you seem to do is try to find something wrong you never seem to point out that the system works just like it is,maybe not to your standards but to the average modeler it is ok.

there are a lot of things in life that work and could be done better but aren't .i will be waiting for the professional test when they are complete.xps has not missed a beat since the day i put it in,no fanboy bullsh!t just straight out fact whether you or anybody else likes it or not

[sweetpea]

Again.......you are only talking about one reason for the system to hop.....High noise levels. XPS never expected to see these levels.....and as we all see......here is a side effect to that along with the antenna. very unfortunate

Trust me, I had a long talk with XPS face to face after my crash (feels like years ago). I asked about the freq hopping and it was explained to my satisfaction. It worked pretty much as I expected it would.


But I would still like to see your results to compare them to what I saw when I had issues. Do they pertain to me?

XPS has also stated that there is a software fix coming very soon for the noise floor freq hopping. Please tell me, you plan to re-accomplish your tests then as well.

[madmax]

Gents, we're throwing a bickering moratorium this weekend. Cool 'r down.

[gargajm]

I am very interested in how this thread turns out.I had the xps system in a 28% Wild-hare. I was flying it all summer, then went to another field to fly. I got several flights in when it all of a sudden lost signal and destroyed the plane. I sent it in and they replaced it for nothing. But I am very leary about putting it in another plane!!

[Mitsu1]

I have an XPS system. Its worked fine (Although I fly mostly in a remote area) .. but it did go to failsafe once, while I believe I was pointing the antenna at the plane. This kinda shook my confidence in the little single stub antenna on the RX. I've always felt if JR & Futaba felt there was a need for diversity antennas, how or why did XPS think they knew better than these larger more established companies.

I'm glad to hear XPS is going to provide a satellite RX or diversity setup, because I was considering going with a Spektrum module/rx just to get the diversity antennas.
... Truth be told, .. I was also alittle swayed by the new AR9100 rx that has the direct heavy duty pwr leads for running A123 batteries. Hope XPS considers doing this as well.