XJet

On another site (that RCU is so paranoid about that they won't allow a link or name to be included here) a test of the interference-resistance of various 2.4GHz radios has been completed.

As had been predicted by many with a background in such things, Futaba's FASST and the JR/Spektrum systems outperformed the systems from XPS and Assan.

Indeed, it appears that the comparatively expensive XPS system was really little better than the cheap Chinese Assan unit when it comes to handling interference.

Neither the Assan nor XPS hopped (no surprise in the case of the Assan because it doesn't claim to hop) when placed under test and both stopped responding, while the JR/Spektrum and FASST systems continued to work perfectly, unaffected by the interference.

So, although the second-tier 2.4GHz systems such as XPS and Assan will work just fine most of the time, they clearly don't provide the same degree of protection against interference that the more expensive "brand-name" 2.4Ghz systems do. And, if you're happy to make do with a second-tier radio, the Assan seems to be better value than XPS -- since it offers pretty much the same functionality and performance for a fraction the price.

dirtybird

My Feedback: (5)

You sure seem to have a vendetta against XPS. What happened did JD snob you sometime?
I have XPS. I bought it when Futaba was still trying to get something out and Spectrum had just released a full system. It works for me. I don''t care if it hops or not.
Its probability of failure from interference is less than that of a switch failure and surely less than that of my thumb.

DadsToysBG

My Feedback: (35)

All X-Jet is saying is that there is a cheaper system on the market that works the same way as XPS. It''s all in the money. I own a business and if I tell my customers the item will do something and it doesn''t then I owe a refund. If not I''m not here long. Dennis

Gordito Volador

My Feedback: (1)

Actually, I appreciate the fact that XJet has kept us up to date with results and test data. Anyone here is free to buy whatever radio they want. I want a product to work as advertised and am willing to pay for quality and want to buy from a company with deep enough pockets to back it up.

DadsToysBG

My Feedback: (35)

Thats the direction I went. I wanted a company that I knew would be around for years to come. When we see crash tests done on cars and one type fails people don''t get on the net and asks why the tester hates that brand of car. They tested four brands of radio systems and three did what they said they would do. The forth did not. Whats the problem? Now I can tell my customers here are the systems, heres what they will do now you pick the one you like best. Very simple. Dennis

slarty

Dennis....

Exactly.... the customer wants facts not suppositions !

Silent-AV8R

The amusing part in all this is the fact that people who have now proven that most, if not all, of the claims made by XPS are either false or misleading are still being branded as "hating" XPS.

None of this is a surprise. I, and many others, called XPS out on their fantastic claims from the day he appeared on the Net. The XPS faithful jumped on that and went wild trying to defend XPS. But here we are over a year later and little of what Jim Drew claimed has proven to be factual. Which is entirely consistent with his previous business history. Yet to this day if you are not 100% enamored with XPS, it is because you "hate" Jim Drew. Not because he has failed to provide the product he said he would.

First he had a "spherical antenna" technology that nobody had ever heard of, including the people who make his RF section.

Then we were told it was ready to go, but he had to wait for months for plastic. But the code was done and proven 100% rock solid. Then it got released and was immediately shown to be lacking.

Then we were told that the TX antenna was OK as a little stub. Until 2 days after release when all of a sudden the modules had the typical antenna retro-fitted to them.

We were told it hopped when the noise floor got too high. It has been shown not to do so.

We were told that antenna diversity was not needed, but now it may be offered simply to make customers happy.

Then XPS was going to partner with Graupner and take over the RC world. Now it looks like Graupner is dropping XPS.

JD was praised for being on the forums, now he has retreated to a single forum which he moderates and strictly controls the content.

Yep, and all of this is true because I "hate" XPS.

Oh well.

dirtybird

My Feedback: (5)

I have to agree that JD puts his mouth where is brain should be sometimes. However:
The product I saw demonstrated worked just fine.
The product I bought works just fine.
I plan to keep using it whether it hops or not. As I said before, its probability of failure due to interference is a lot less than a lot of other factors.
There are a lot of things being made in China that are cheaper. Most of the stuff I have is made in China. Its interesting that the Chinese made ESC I have, has US made HV transistors. It seems if we make a better product people will buy it
Xtreme products are probably not the best buy now. Airtronics will sell you a whole radio for about the same price as Xtremes module + receiver. And its an FHSS system for those of that like to have a radio that hops around. Where is Airtronics made? Tiwan? Isn''t that China?

c/f

My Feedback: (1)

Xjet,

You can put a link in and put * beteen the offending letters RCU filters with, thus the user need only copy and paste then remove * to view.

Silent.

I just got back from Germany and Graupner has a 2008 catalog with 3 pages of adverts and claims of the XPS.

Robbe does FASST.

Secondly JD was @ Toledo with a Graupner turbine in his booth. Once again he is running his mouth with claims of performance noone has a clue where they come from and the actual specs are far differant on Graupners literature.

Actualy I remeber JD started XPS almost 3 years ago (runryder) with his outragous claims of performance. The one thing I thought interesting all this time was his claim that the proportional channels where limitless with his processing speeds, yet he came out with less than the competitors.

In the end I look at resale to see just how good a product is. XPS and ASSAN will sit on a for sale for weeks and SPektrum/FASST are gone within the hour provided they dont exceed MAP, and sometimes when availability is short you can get higher than MAP.

XJet

Dead right.

I have no "vendetta" against XPS or JD but I do get really annoyed when I see someone with only a passing understanding of the (RF) technology they''re using trying to bamboozle and deceive people.

I was one of the original critics of JD''s claims in respect to XPS and *all* of my criticisms and predictions as to the limitations of the system (despite denials by JD) have ultimately turned out to be true.

In my case, once it became obvious that he couldn''t argue the facts (since they weren''t on his side), JD resorted to character assassination but that didn''t worry me, I''ve been called worse by others whose silly claims I''ve challenged before. Sticks and stones etc.

However, here''s the score to date:

1. "experts" say the tiny 1/4-wave stub antenna on the transmitter module is inadquate JD says that''s BS and he''s extensively tested the system to prove that it''s all you''ll ever need. However, at the system''s very first large public demonstration a dipole is hastily fitted to the transmitter being used and now dipoles are standard equipment. "experts" 1, JD 0

2. "experts" say there is no such thing as a "spherical" radiation pattern and that the laws of physics make such a thing an impossibility JD says there is and that his design is a unique 8-element one that is patent pending. MaxStream (who designed and make the RF module) deny the spherical antenna and say it''s just a plain 1/4-wave whip (why would *they* lie about such things?). JD is challenged to provide either the 3D radiation map or even a picture of this mythical antenna. He fails to do so because he can''t. "experts" 2, JD 0

3. "experts" say even a spherical antenna (if it existed which it clearly doesn''t) won''t eliminate the need for antenna /receiver diversity. JD says that''s BS and his system doesn''t need satellite receivers for diversity. Less than a year later, JD announces plans to deliver satellite receivers for those flying large models (why?). "experts" 3, JD 0

4. "experts" do some tests and discover that XPS does not hop as claimed. JD says it *does* hop, but only under special circumstances and promises to deliver a video of the hopping. He then says the only time it won''t hop is when the entire band is saturated because in such cases, there''s no point in hopping and no SS system will work anyway. "Experts" test four systems side-by-side under identical conditions where only a portion of the band is affected by interference. XPS fails to hop and actually locks-up (even though there is somewhere to hop) while JR/Spektrum and FASST continue to work unaffected. "experts" 4, JD 0

So that''s a quick history of the situation for those who haven''t been following things.

The common thread is that JD makes claims which show either a worrying naivety or a deliberate intention to deceive.

There is no malice on the part of those who have disputed JD''s claims, simply a desire to protect others from the hype and BS that JD is claiming for his system.

Of course it has to be said that XPS does work satisfactorily in many cases. There are thousands of XPS users who have never had a problem and some of those have an almost religious devotion to the product and its developer. They choose to ignore the fact that the product they''re using isn''t what was advertised and that''s their right, I''ve got no problem with that, it''s their right to do so.

However, I think those who don''t have the technical background required to check JD''s claims out for themselves have a right to know that they''re being told a lot of stuff that simply isn''t true.

How would you feel if you were told you were buying a Ferrari but were delivered a look-alike fiberglass knock-off with a VW engine?

Yes sure, the look-alike will still attract envious looks and get you down to the shops. It might even get you to the beach for your vacation but it''s *not* a Ferrari and if you''re challenged to a drag-race by a bit of interference, you will find yourself sadly disappointed with the outcome.

People have a right to know the truth about the products they''re buying and I have to admit to being very disappointed that some of those who are so strongly pro-XPS describe anyone who dares to bring facts into the argument as "XPS-haters" or "nay-sayers".

Their only response to these facts are to use phrases that almost inevitably start with "JD says..." which, as we''ve seen by his track-record of being less than generous with the truth, carries no weight at all.

Maybe they''re 100% happy with their XPS system, which is great but to try and devalue the hard work of those who have taken the time to investigate and debunk the ridiculous claims made by JD does a huge disservice to those others who simply want to know what''s true and what''s not. Will the XPS fan-boys be prepared to replace the crashed models of those who are told that the "experts" are just XPS-haters when they are struck down by interference that other 2.4GHz systems fly through unaffected? I think not.

jmohn

Wow, sure glad I didn''t go with that system.

I recently, purchased a JR 9303x and it''s been great. I started slamming Spektrum a while back when their systems were locking up in mid-air and got told off by a bunch of people that there weren''t any issues with the product. I few months later they come out with an upgrade to solve the lock out or "brown out" condition. There are always people out there that will stay with a sinking ship no matter how cold the water is. At least Spektrum and Horrizon stepped up and fixed the problem before someone got hurt. A lock out in mid air (I had four) is a very dangerous situation, especialy when you fly around residential areas and streets. A large plane 6+ pounds can do a lot of damage when it''s out of control.

If this the XPS system can lock out while it reboots that''s a bad situation and should be fixed.


Jeff

slarty

Silent,

Where did you see / read / hear this ???

chrisF test pilot

I would like to hear that also, as that certainly isnt the story I have gotten.

Oh, and keep up the good work XJet. No matter where I go I just cant get away from you posting about how bad XPS is.

Gordito Volador

My Feedback: (1)

I agree, keep up the good work XJET!

XJet

Thanks Chris :-)

I just wish I didn''t have to and that people could simply get the truth about what XPS will and won''t do direct from the XPS website.

Assan seem to be doing *very* well (places like HC find it hard to keep their systems in stock) despite a lack of telemetry, frequency hopping or satellite receivers so I don''t think it would hurt XPS one little bit to fess up to the limitations of their system in fact it might even improve their reputation and kill all the bad press they''re currently copping.

The deeper the hole of distrust that JD digs the harder it will be to climb out.

Hell it''s *not* a bad system it''s just not the system he claims it is and doesn''t have to features he boasts the tests prove this.

chrisF test pilot

Why do you care? The only people it seems to bother are you and a few other individuals. And you can play the no agenda line all you want, you do have an agenda.

Without having the parameters under which the system was designed to change channels the test proves nothing except that it wont hop when flooded with narrowband noise. Which JD has said all along would be the case. The system works the way he claims it does, even if you dont like him or his marketing style. There have been just as many people if not more make that claim than that it doesnt. BUt they are happy using the system and enjoying flying.

But hey, you''re the expert right..

XJet

Yes, you''re right, I do have an agenda.

My agenda is to make sure that people who don''t have the technical background to understand they''re being lied to are not hoodwinked by JD and XPS.

I actually get really annoyed when I see innocent folks being fed a load of BS about a product, how it works and what it does.

Forgive me for caring about the fact that people are being duped.

Wrong.

It proves that the ability of XPS (and Assan) to cope with interference in what is sometimes a very hostile band is inferior to that of FASST and JR/Spektrum and that is very important. In the case of Assan it''s not quite so important because it doesn''t make the same outrageous and unsubstantiated claims that XPS does.

XPS has been sold as being wonderfully resistant to interference because it can hop to another frequency.

This test proves that it doesn''t

This test shows that FASST and JR/Spektrum continue to operate unaffected in the face of interference, while XPS crashes and burns. That is not what people expect after reading the hype from XPS.

And what good is frequency hopping if it only works when the interference is nice enough to conform to some incredibly narrow set of parameters that suit JD? Neither JR/Spektrum nor FASST seem to be limited to such narrow parameters when it comes to coping with interference, they continue to operate unaffected and that clearly makes XPS inferior in this regard.

Wrong again.

JD said it would change frequencies when interference was encountered. It was only *AFTER* independent tests proved that it wouldn''t change frequencies that he changed his tune and came up with this "flooded with narrowband noise" caveat. How convenient.

And the tests that were conducted most recently didn''t flood the entire band with narrowband noise they simply raised the noise floor on a portion of the band. Under JD''s own rules, XPS should have hopped because there was clear-space elsewhere on the band that it could have jumped to. The fact that other systems continued to operate unaffected proves that the entire band was *not* flooded in these tests.

It depends on whether you''re listening to the original claims (on which many based their purchasing decisions), today''s claims (which have been modified to suit the facts) or tomorrows claims which will doubtless be modified again to reflect the way these latest tests have caught JD''s claims out again.

I gather "marketing style" is a euphemism for "outright lies and deception" in this case.

I''ll take your word for that.

Silent-AV8R

I am trying to find the forum where I read this. It had a link to another forum. So let me qualify this one as third hand at best.

Silent-AV8R

As noted above I am trying to relocate the link. I''ll post when I can. But let''s not focus on this one. What about ALL the other things JD/XPS has stated that just simply are not true??

dirtybird

My Feedback: (5)

I have a question. Are there devices that turn on on any channel within the 2.4 GHZ without checking to see if that channel is being used? Not the FSST systems. They don''t stay there long enough to be a problem.

DadsToysBG

My Feedback: (35)

Spektrum scans for two open channels before it brodcasts. Tests have shown that Spextrum will work with more then 40 radios at the same time. As I stated in another forum what happens down the line with you have Spektrum and Futaba in the air and pits all on and XPS with it''s limited channel use (I believe 11) be able to even be usable.
A question to X-jet. Does Futaba always start the scan at the same point, or does it scan a open channel and start from there?
Dennis

dirtybird

My Feedback: (5)

And how many sets would that be?

DadsToysBG

My Feedback: (35)

Thats the question I''m asking. If XPS only has 11 channels and you have the other two radio systems all working. And since XPS will not hop, can it find a open channel to operate. It works on a single channel. We know it will scan looking for a open one. The question remains will it find one. Remember Spextrum picks 2 of 40 and Futaba jumps around on 36. Spektrum have been tested up to 46 radios. Would this limit it''s use? Dennis

Julez

I''m not Xjet, but I understand, that Fasst scans before switching on. If it finds the 2.4GHz band saturated to an extend that would make flights risky, it does not start to transmit. If this is not the case, it will start to transmit on all channels. Fasst does not care for individual channels, it cares for the big picture as a whole.

tadawson

That has not been proven! All that has been proven is that the testers who have made attempts have been unable to create the correct test environment . . . . others have seen evidence of in-flight frequency changes on multiple occasions . . .

- Tim