Independent tests prove lack of frequency hopping with XPS

[Kiwi]

Guys I promise you all this thread is far from over and I am doing everything I can to get Xjet a setup of all four available systems so the shootout is fair and equal for everyone.

I figure if he can test each system against the same level of background noise we should be able to determine what is best and what just plain does not work good at all. No matter what the result it must be good for everyone concerned. We as users and the manufacturers themselves. I will repeat myself yet again when I say members are asking why we cannot have some form of product testing and fair and open reporting done by some of the experts we have here on site as members. Well unless I am mistaken what the heck do you think we are doing here???

The thing that puzzles me most so far in this thread is the constant inference that Xjet is slamming XPS with unfounded accusations and refering to opinions as opposed to facts.

Its obviously the reverse. XPS does not frequency hop when overwhelmed by a strong 2.4Ghz signal. XPS have admitted that and they say they have a fix on the way coming next year. In the mean time if I was flying XPS I would be horribly damned concerned about flying it on anything I was not totally prepared to crash and loose, let alone cause some third party injury or damage.

What I did not see here or on any of the sites JD associates himself with is a warning to all users stating clearly that his system has limitations that USERS NEED TO BE AWARE OF. Xjet has at least woken a few of us up to the potential. Note I said potential, not absolute.

Yes Spektrum had voltage issues and that was found and sorted by the RC modelling community as much as the manufacturer, but they did come out and say VOLTAGE IS AN ISSUE and they recommended some fixes.

Gents if we are to be a fair and open minded community we need free and open debate, we need to also respect the rights of the manufacturer to respond, but the in and out plain nonsensicle bickering over who said what and when does not shed one iota of light on what could be a very important issue for XPS and others, maybe.


I see the answer as being dead simple. If you have an XPS unit in your plane and you trust it go fly it. If your a little bit conservative and you would like to see someone try and prove the strengths and weaknesses of the system then patiently wait for the guy to do what he promised.

As for me I dont need any darned video. I know what the answer will be because XPS said they dont hop if the hit is sudden. I want to see it hop if the hit is slight now as well.

Anyone who has even the slightest interest in seeing some factual results on what how and why with 2.4 Ghz needs to stay subscibed to this thread.

If not it is as easy as clicking the unsubscribe button and leave this place to those who want to learn and not from opiniated people, but people prepared to put the time and effort into testing something.

[bob_nj]

Well said!I'm not going anywhere...

[sweetpea]

So in a nutshell you have the companies learning from each other I'm very sure.......

XPS...... Freq does not hop with sudden increase in noise floor past a certain threshold.
--XPS states that this was because a sudden increase would typically cover the entire band so they software limited it not to hop
--XPS has a software fix for this coming soon so it will hop no matter what
--No independant testing has been done on gradual increase to date to verify it hops

Spektrum......battery voltage issue
--took numerous consumers to complain about unexplained crashes
--I believe there were some not so official testing by consumers done
--There is no "fix" for the problem, only acknowledgement from the company it exists now
--Band-aid solutions include: using a powerbox, more battery or the capacitor
--There were some orginal failures that a recall was made in the 6000 series rx's. As well as the 9000 series requires you to glue a capacitor down in the RX (I know I've done that to 2 of them)

FASST...couple of lockouts I've read about but not much else.
--modules should be hitting the stores and consumers in the next couple of weeks
--so far FASST is for Futaba only, so this will limit the number of examples

ASSAN and the other 2.4 companies....to new and not much reporting going on. They also appear to be the most limited systems as far as diversity. May change in the near future

72mhz....prone to all sorts of interference and the dreaded shootdowns. But a viable solution that has worked good for the last 20yrs or so if everyone around you respects the freq board

[jonkoppisch]

You should probably add battery voltage issues to xps... At least that's 1 of the things that they threw at me It has been reported pretty often with the xps units as well, although, probably not as much as with spektrum. That could simply be accounted for though by the larger #'s of spektrum units that are sold.

That and not setting the failsafe will evidently cause you to crash as well

[Pale Rider]

You can also add to your Spektrum list that the reboot time on the last 2 rx's developed (r921 and ar9100) is less than 1/2 second.

[snap a saurus]

I thought I knew the 2.4 Ghz system, there is more to it and hopefully most of the problems will be fixed so we can have a reliable and safe system.

[sweetpea]

	Quote: Originally Posted by jonkoppisch
	You should probably add battery voltage issues to xps... At least that's 1 of the things that they threw at me It has been reported pretty often with the xps units as well, although, probably not as much as with spektrum. That could simply be accounted for though by the larger #'s of spektrum units that are sold. That and not setting the failsafe will evidently cause you to crash as well

2 things.....
1)I don't think the large number of units is the issue as much as XPS has not released the 6ch rx (parkflyer/electric) yet. This is where most of the voltage issues showed up was from folks running electric airplanes where your voltage is going to drop faster (that and the giant scale use of 8711's) If they had been released at the same time or so, then voltage may have been an issue for both, but as it stands, 90% of the folks now know to watch out for voltage on 2.4 gear.

Failsafe is not an issue in my book.....on any RX you should be setting a failsafe of your chosing. Not setting your failsafe is not going to cause you to crash.

2) XPS reboot voltage is less than Spektrum so I left it out as a real issue. It looks as though Spektrum is the highest reboot voltage on the market.

	Quote: Originally Posted by Pale Rider
	You can also add to your Spektrum list that the reboot time on the last 2 rx's developed (r921 and ar9100) is less than 1/2 second.

That is a definite improvement over the 3 or 4 second reboot but not a fix for the battery voltage issue. If my rx is shutting down on low voltage it is still shutting down (no matter how short of time) and when there is still enough juice to run my servos why is my RX shutting down?

[jonkoppisch]

I was just going by what they claimed on me when my jet crashed... It was a power problem (yet there was 2 battery packs that tested good under load), then the receiver failsafe wasn't set. Then a servo or (which I'm using in a new plane with no problems) ....

Hey, quick question. With the unlimited warranty, I wonder if there would be any replacement issues if I start using the xps in combat

[sweetpea]

they now claim full replacement for any cause of failure. Though full contact combat may not be covered since you are intentially putting the unit in harms way. A simple email would let you know for sure

[jonkoppisch]

I could always claim that I had the failsafe set wrong

Before anyone panics... JUST KIDDING!!!

[Pale Rider]

	Quote: Originally Posted by sweetpea
	That is a definite improvement over the 3 or 4 second reboot but not a fix for the battery voltage issue. If my rx is shutting down on low voltage it is still shutting down (no matter how short of time) and when there is still enough juice to run my servos why is my RX shutting down?

IMO the low voltage reboot issue is really a moot point. I have no experience with electric planes so it may be a different story there, but there is no reason to let your rx packs go below 6v (assuming your using 6v packs) in glow or gas planes. Yes S---t happens and possibly something may occur while you are flying, but the lower the voltage gets the more sluggish the controls so I would think a pilot would get an indication of a problem before the voltage gets under 4v. All the more reason to check between flights with a 1-2A load.

[sweetpea]

	Quote: Originally Posted by Pale Rider
	IMO the low voltage reboot issue is really a moot point. I have no experience with electric planes so it may be a different story there, but there is no reason to let your rx packs go below 6v (assuming your using 6v packs) in glow or gas planes. Yes S---t happens and possibly something may occur while you are flying, but the lower the voltage gets the more sluggish the controls so I would think a pilot would get an indication of a problem before the voltage gets under 4v. All the more reason to check between flights with a 1-2A load.

I agree 100% on this.........I was just looking out for those electric flyers out there in stating problems of each system so they may make a more informed decision based on facts. What I laid out was just that......facts, backed by the manufacturers