Kiwi's XPS test results are up.

[Toumal]

I do recall negative reviews in FMT (a cheap jet turbine, for example) but of course it's right that ads=profit. Anyway, here's hoping for the truth. - Not bashing, mind you.

[4*60]

	Quote: Originally Posted by phippsj
	P.S. Anyone want to buy some used XPS equipment?

What have you got?

[phippsj]

	Quote: Originally Posted by 4*60
	What have you got?

I have the TX module for Futaba 9C and two 10-channel receivers. All are in like-new condition and work great. No problems at all over the past year.

PM me with an offer.

[capgains]

	Quote: Originally Posted by Simpleton
	That's why I was skeptical when RC Reports was mentioned. Unless they have an RF lab and skilled techs on the payroll (yeah, right), then their honest review of XPS might come off as positive. Unless they flew it long enough for a lock out to occur, they might well conclude that it works just fine and write a glowing review based on their limited experience with the system. I doubt many magazines would have the staff to do an in-depth frequency hopping expose' of any 2.4 system. If they hook it up and it works, then that's likely what they'll report.

Yeah but cripes. Who does that kind of testing anyway? Most reviews are written from the way a consumer would use the product. They don't throw every radio product on the analyzer, or tear apart the lithium battery to see how pure the lithium is. They don't drink the glow fuel to see if it will really kill you, or make you blind. They simply review it from a standpoint of how a person would use it.

So what you are saying is that a review of XPS might come off as successful, because it didn't fail.... unless they flew it long enough. Well how long would that be? I fly in rural Oregon. That might be..... forever. So far it has.

The kind of testing you are suggesting would simply be failure testing... as in... what would it take to make equipment fail. The variables would be completely useless to modelers who are simply using the stuff under normal conditions.

Every ARF would fail the extreme gravity test, every engine would fail if you injected sand into the cylinder, every radio would fail if you threw it in the microwave for 10 minutes, every battery would fail if you shorted it etc, etc.

Magazine reviews are meant to bring information at a user level in a timely mannner. Who would want to read about a product that was brought to market a year ago, now that some long term testing was done? Wow... turns out that Lipo batteries really do weigh less and have longer output... that's news.

[Black Sheep]

It kind of tickles me to see these sort of things. So we are testing to prove failure.
I use both 36meg and 2.4 here in Oz and it was a 36meg failure that caused me to switch to 2.4, and the lack of systems available that caused me to choose XPS so.......
If it works till it doesn't, then I shouldn't use 36 meg anymore, right? Same thing that is being said about XPS. I've used XPS for about a year now with around 180 flights and it is still rock solid. I might add that I'm flying within 6 kilometers from town and XPS is supposed to have an 8 kilometer range so I should have got some sort of lockout from 2.4 systems in town. I also flew it about 3 kilometers from town on the other side at the airport and the XPS system is, has been rock solid where 36meg has failed me.
I don't really care about the hopping feature, all I know is that it has fixed my problem. I do wish some of the additions and features were available though.
Great effort though to all those who have tried to see if the system holds up to the claims but I think some things that are being said can be applied to 36/72meg also and when you think about it, it is quite a silly statement (It works till it doesn't) and it holds true for anything else for that matter. Everything works till it doesn't!
Just my experiences and not knocking or supporting anything in particular as I still use both systems. Mind you, I'll be buying the new JR 2.4 radio soon.
Keep up the good work.

[XJet]

	Quote: Originally Posted by capgains
	Every ARF would fail the extreme gravity test, every engine would fail if you injected sand into the cylinder, every radio would fail if you threw it in the microwave for 10 minutes, every battery would fail if you shorted it etc, etc.

But there is one important thing that you learn from "testing to failure" and that is exactly which system(s) have the greatest headroom (ie: capacity to cope with strong interference in the case of 2.4GHz).

Given how new the technology is and how few people have any idea just how benign or hostile the 2.4GHz profile of their flying field is, this information is *very* useful to anyone considering the move.

Most people like a little insurance against the unexpected or unlikely disaster. Your home and your car are insured aren't they?

Well when you know which system(s) provide better protection against interference you're able to invest in some "insurance" if you feel so inclined.

There'll always be people who don't bother insuring their valuables and most of them will never have a problem. However, accidents (and interference) do happen, which is why the vast majority of us perfer to play it safe.

In the case of your house insurance, if the place is uninsured and it burns down the only one harmed is you - but with a model, if it gets shot down by interference there may be innocent bystanders who are placed in jeopardy. So, if you're flying a large or fast model, choosing the most resilient system is the sensible and ethical thing to do -- isn't it?

[Toumal]

	Quote: Originally Posted by Black Sheep
	It kind of tickles me to see these sort of things. So we are testing to prove failure. I use both 36meg and 2.4 here in Oz and it was a 36meg failure that caused me to switch to 2.4, and the lack of systems available that caused me to choose XPS so....... If it works till it doesn't, then I shouldn't use 36 meg anymore, right? Same thing that is being said about XPS.

Look, if XPS works for you, then that's great! I really hope that you don't get any problems!

However, at the end of the day the point is not to find something bad about XPS and jump up and down about it, but to set the facts straight. Indeed, 2.4 GHz transmissions are less susceptible to interference caused by your motor, your ESC etc. and I do believe that it's an improvement in general.

However, where I live 35MHz is reserved for RC planes and helicopters, whereas 2.4GHz is not reserved for anything, so if you fly a single-channel system you're basically playing russian roulette. Doesn't matter if there's no 2.4GHz transmitter nearby that you know of, doesn't matter if you put in 180 successful flights. Tomorrow someone will set up a wireless LAN in a barn or a severa-watts 2.4GHz video transmitter bought in China, and he or she might come up on the same channel as your XPS system. You never know such things, and saying "it won't happen to me" is very... optimistic.

I spoke to someone who's actually flying XPS here in Austria (where it's called IFS), and he actually switched from Futaba FASST! I asked him why, and he said that he lost a plane with FASST inside. Bird fell down with no controls, he went to the crash site, and according to him everything worked fine when he got there. There's ten thousand things that can go wrong: Was it a loose cable? Maybe the RX is bad, or the antenna connector is loose? Maybe vibration caused the failure, maybe there was intermittent battery contact. And maybe it was FASST?
At the end of the day, he can't claim to *know* whether FASST failed based on that incident alone. If he would've had a logger installed... maybe that would be a different story. In my opinion his decision was more based on gut feeling than on facts, but that's my opinion. Everyone is entitled to their own opinion, and thus, also their own mistakes.

I would treat any report about XPS crashes with the same scrutiny and grain-of-salt attitude. However, we're talking about facts here:
1) XPS can't hop if there's someone on your frequency, unless it's a gradual thing that allows the RX to tell the TX about the upcoming trouble.
2) XPS has no antenna diversity and the claims about spherical radiation patterns is, at best, an unrealistic and idealistic approximation, and at worst, nothing but marketing babble.
3) The guy responsible for the design is contradicting himself.

These two points are what it's about. It's not about saturation, as JD keeps bringing up, and it's not about advertising for Futaba or Spektrum, because there's no such thing as a perfect system. All I'm saying is that it takes a lot less to shoot down XPS via interference than FASST or Spektrum, and Kiwi proved that this issue is real and not an exaggeration or just a far-out remote possibilty.



I really really hope that you never get any trouble with XPS, and if it works for you then that's good. I don't call you names for using XPS, and if you believe that it's the better system, more power to you. I just hope you keep in mind the known limitations of XPS, just as I do with my FASST system (as if the thread about FASST temperature problems wasn't already popular enough )

If you can, do yourself a favor and fly with a logger. That way, if something happens, at least you know whether the RX still worked or not.

[Black Sheep]

	Quote: Originally Posted by Toumal
	Look, if XPS works for you, then that's great! I really hope that you don't get any problems! So do I! As I mentioned, I was kind of forced to use XPS as no other system was available to use with JR. That is not the case now as all kinds of new systems are now out. I'm not saying XPS is better, I'm just saying that what people are saying has not been experienced here with my system. Not saying it will never happen. Personnally, I'd prefer JR equipment. However, at the end of the day the point is not to find something bad about XPS and jump up and down about it, but to set the facts straight. Indeed, 2.4 GHz transmissions are less susceptible to interference caused by your motor, your ESC etc. and I do believe that it's an improvement in general. I agree. Read above. However, where I live 35MHz is reserved for RC planes and helicopters, whereas 2.4GHz is not reserved for anything, so if you fly a single-channel system you're basically playing russian roulette. Doesn't matter if there's no 2.4GHz transmitter nearby that you know of, doesn't matter if you put in 180 successful flights. Tomorrow someone will set up a wireless LAN in a barn or a severa-watts 2.4GHz video transmitter bought in China, and he or she might come up on the same channel as your XPS system. You never know such things, and saying "it won't happen to me" is very... optimistic. I never said it won't happen to me. Actually, the property next to the flying field has a wireless LAN and I've not experienced any dramas to date. Not saying it will never happen, just saying it has not happened to date. I spoke to someone who's actually flying XPS here in Austria (where it's called IFS), and he actually switched from Futaba FASST! I asked him why, and he said that he lost a plane with FASST inside. Bird fell down with no controls, he went to the crash site, and according to him everything worked fine when he got there. There's ten thousand things that can go wrong: Was it a loose cable? Maybe the RX is bad, or the antenna connector is loose? Maybe vibration caused the failure, maybe there was intermittent battery contact. And maybe it was FASST? At the end of the day, he can't claim to *know* whether FASST failed based on that incident alone. If he would've had a logger installed... maybe that would be a different story. In my opinion his decision was more based on gut feeling than on facts, but that's my opinion. Everyone is entitled to their own opinion, and thus, also their own mistakes. I would treat any report about XPS crashes with the same scrutiny and grain-of-salt attitude. However, we're talking about facts here: 1) XPS can't hop if there's someone on your frequency, unless it's a gradual thing that allows the RX to tell the TX about the upcoming trouble. Actually, the advertising here for XPS here say it will only hop "when there is POTENTIAL interferrance". The tests have been looking for hopping when interferrence is experienced. See the difference? So no false advertizing there, just the way people read it. 2) XPS has no antenna diversity and the claims about spherical radiation patterns is, at best, an unrealistic and idealistic approximation, and at worst, nothing but marketing babble. My antenna is way down in the belly of the plane and it seems to work fine there. I'm not disputing the claims about the antenna patterns, just a comment. 3) The guy responsible for the design is contradicting himself. These two points are what it's about. It's not about saturation, as JD keeps bringing up, and it's not about advertising for Futaba or Spektrum, because there's no such thing as a perfect system. All I'm saying is that it takes a lot less to shoot down XPS via interference than FASST or Spektrum, and Kiwi proved that this issue is real and not an exaggeration or just a far-out remote possibilty. That is quite possibly true, which is one of the reasons I'll be switching to the new JR system. Maybe it is not so much the equipment but the location the equipment is operated that is the problem? I really really hope that you never get any trouble with XPS, and if it works for you then that's good. I don't call you names for using XPS, and if you believe that it's the better system, more power to you. I just hope you keep in mind the known limitations of XPS, just as I do with my FASST system (as if the thread about FASST temperature problems wasn't already popular enough ) I never said you called me names and I never said it is a better system. If you can, do yourself a favor and fly with a logger. That way, if something happens, at least you know whether the RX still worked or not.

As noted earlier, that is pointless as I'll be changing to the new JR system shortly for the big planes. Until I do so, I'm only flying the smaller ones on 36 meg.


I can't even flog the XPS gear off now as no one will buy it because of these sort of threads going around. Guess I'll just throw it in the bin.
I want to remind you that I appreciate Kiwi's efforts and Xjet and everyone else who is trying to get to bottom of this. I'm no techie and have to rely on people like this and the wider community to advise us all of any potential problems. Thanks guys.
The point of my posting is exampled above with all the misconseptions and mis-reading of things with people reading things into stuff that's not there.
There may well be problems as proven by the tests that have been done by Kiwi and Xjet however how do you explain the guys in Melbourne flying XPS in a major metro area (with over a million poeple) with over 1000 flights on all types of aircraft from sailplanes to helis, turbines and large scale aerobatic and not one issue?
I also have not experienced any dramas but that doesn't mean they don't exsist. Not saying XPS is a better system, just saying the environment that is being tested for must not be the same here?? Don't know.

[capgains]

	Quote: Originally Posted by XJet
	But there is one important thing that you learn from "testing to failure" and that is exactly which system(s) have the greatest headroom (ie: capacity to cope with strong interference in the case of 2.4GHz). Given how new the technology is and how few people have any idea just how benign or hostile the 2.4GHz profile of their flying field is, this information is *very* useful to anyone considering the move. Most people like a little insurance against the unexpected or unlikely disaster. Your home and your car are insured aren't they? Well when you know which system(s) provide better protection against interference you're able to invest in some "insurance" if you feel so inclined. There'll always be people who don't bother insuring their valuables and most of them will never have a problem. However, accidents (and interference) do happen, which is why the vast majority of us perfer to play it safe. In the case of your house insurance, if the place is uninsured and it burns down the only one harmed is you - but with a model, if it gets shot down by interference there may be innocent bystanders who are placed in jeopardy. So, if you're flying a large or fast model, choosing the most resilient system is the sensible and ethical thing to do -- isn't it?

Xjet, we are talking the difference between consumer advocate, consumer review. I know you might have trouble with that because you kind of hold yourself out as a consumer advocate type. As far as magazines go, I think they are designed to provide information given by a fellow modeler. You get alot more information than you get from the manufacturer of the product. And as in the case of RCR Magazine, the information is independant. Even though the advertiser places ads in the magazine, Gordon has made it very clear that all of the products they review are purchased by the magazine without the manufacturer's notice. They are reviewed, and if a problem arises they contact the manufacturer, and give them a chance to provide recourse, solution etc. I have seen reviews where a product got a black eye. (Can't say that for some magazines.... Still mad about that Kyosho Gee Bee Z that got rave reviews... and one of the top 5 ARFs that year)

As for the ethical decision model, and flying R/C planes.... Aw come on. When was the last time your bought an R/C product because you thought it was the ethical thing to do? (not Saftey reasons, you are infering accountability) If you used that train of thought, you would never fly, period... too much risk. Face it, the reason you buy a radio system, is because you like it, think it will work right, and not crash your stuff. You don't buy one because you are afraid any other brand will hurt someone. That's like saying I bought an RSC engine because it is shaped so that if I fly it into my buddy's A@#$, it will be much easier to remove than brand X. We fly in an environment of burning fuel, noise, flammable and explosive batteries, spinning ginso propellers, 1200 degree exhaust temps, hovering planes bigger than we are all controlled by invisible radio waves..... What can go wrong? Everything. We each assume the risk and try to be safe.

But the assumption that we have used ethics as part of making a decision on buying R/C equipment is ridiculous.

[GBR2]

One of the main reasons I purchased XPS equipment in the first place was for frequency redundancy.

JD orginally posted this:
“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.”

and this:
JD from November 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."

I don't know how others might read this but to me it says that if interference starts to show up on the XPS channel in use, BAM, the system can hop away. The videos Tychoc and Kiwi did clearly show this not to be the case.

I don't know about the "ethical thing to do" but one of the nice things about the FASST, Airtronics and Spektrum systems is the built in frequency redundancy which we don't have with 72MHz, and a more secure RF link was one of the things I wanted that 2.4GHz could deliver. I thought I got that with XPS but as far as I can tell, I did not. The system obviously works but then again so does the Assan system but I never would have bought it (and didn't) because I knew it didn't have built in frequency redundancy. My original purchase might not have been bought for "ethical" reasons but it certainly was done for greater safety, or so I thought.

[Simpleton]

capgains, the thing is - You are using it with great success in rural Oregon. It'd probably work where I live. If RC Report was only sold to modelers in remote rural areas, there might indeed be no cause for alarm. But RC Report is sold to modelers who might not live in a rural area. It's not fair (or ethical, or wise) to promote a system that passed itself off as a spread spectrum, frequency hopping device to unsuspecting modelers who will believe it is (and therefore works) based on a magazine review.

I'm positive RC Reports wouldn't intentionally give a thumbs up to a system that didn't do what it was advertised to, but Gordon has stated before that he distrusts (or tends to not use/rely on) information gathered from the internet. Well, that's where the non-hopping proof is located. Would Gordon know that XPS doesn't hop? Who knows, he might even pass on a review if he knew it didn't perform as advertised. I don't know what type of 2.4Ghz activity is present where RC Reports reports from, it might fail on them and be a moot point.

The point is, if all you had to go on was the manufacturer's claim that it was a spread spectrum, frequency hopping device, and you had no way to verify this, and the system worked in the location where the review was done, you could very well say that it worked as advertised and be dead wrong.

[XJet]

	Quote: Originally Posted by capgains
	As for the ethical decision model, and flying R/C planes.... Aw come on. When was the last time your bought an R/C product because you thought it was the ethical thing to do? (not Saftey reasons, you are infering accountability)

Gosh, I must be the exception then.

I have a 2.4Ghz system without failsafes. I use it on my .40-sized profiles but I won't use it on my larger planes because it has no failsafe.

I figure that no large model should fly without failsafe, so I use a JR PCM system in my 30% Extra.

Failsafes won't save my Extra from becoming a pile of dust if I get hit but it does mean that if somethin ggoes wrong, at least I know the engine won't be at full throttle and potentially tearing the flesh from people's bones.

That's the ethical/moral perspective and one that *I* take into account.

[capgains]

Simpleton,
You pretty well hit on it... intention. IMHO, RCR does not intentionally say that a thing is good if they know it isn't. (Once again I wince at the magazine that is owned by a MAJOR mail order company that said the Kyosho Gee Bee Z was a great ARF) What you guys are calling for is long term testing, and endurance testing. Out of the scope of a review. One of the great things about the internet, is that we can communicate with each other. But there is also content that must be taken with a grain of salt too.

Xjet, ethics was not the motivation to buy that 2.4 radio. You bought it because it was cheap. Once you had it, you realized that you didn't trust it. And you can kill someone with a .40 sized plane as easily as your big Extra. So if Ethics and the protection of fellow man were your motivation to buy the 2.4 radio... you would have never purchased it.

However, your sense of responsibility and safety is quite admirable. If you indeed follow your policy on using failsafe on your equipment, then that shows you take accountability seriously.

The real truth is nobody is buying 2.4ghz systems because they think they are safer, and you will never see that in an advertiser's claim.

People buy 2.4ghz systems because:

They don't want to wait for a frequency pin
They don't want to get shot down by another radio
They don't have issues with metal to metal contact or igntion noise (within reason)
Many of them can operate at one time

That's about it.

[tadawson]

	Quote: Originally Posted by capgains
	People buy 2.4ghz systems because: They don't want to wait for a frequency pin They don't want to get shot down by another radio They don't have issues with metal to metal contact or igntion noise (within reason) Many of them can operate at one time That's about it.

Not to forget:

Everyone else got one, so why not? (Lemming theory . . . follow the herd, at times without any thought involved . . . ).


- Tim

[alfred]

	Quote: Originally Posted by tadawson
	Not to forget: Everyone else got one, so why not? (Lemming theory . . . follow the herd, at times without any thought involved . . . ). - Tim

True And also lots of us are techno buffs. Doesn't mean we just follow the herd.