Kiwi's XPS test results are up.

[zoomer260]

Hey that was a great show !! Can't believe that JD did a "drive by" on the thread with no offer to straighten out his ideas. Probabley posted here and then went to RCU to delete more posts !

I've tried other RC sites and just don't really see the attraction. More stuff in the swapshops I reckon.

[BigD]

Kiwi,

Thank you for taking the time and effort to bring to light the different strengths and weaknesses of the current crop of Spread Spectrum systems available to R/C. Given the size and power of R/C aircraft today if is essential that we understand the limitations of these systems to help ensure everyone's safety at the flying field. It is unfortunate that the manufacturers themselves have not done a better job of describing their systems or publicly recognizing the failure modes so that we can operate them with full knowledge. As someone that has spent some time working in RF systems in the past, I have an appreciation for the rising noise floor in the 2.4Ghz band as well as the ability of some sources to create noticeable interference under certain conditions. Thank you for illustrating this in a clear and understandable manner. Kudos...

BigD (KV4DN)

[sweetpea]

nice vids Kiwi. Glad to know the results of the other systems in the same setup.

[easytiger]

	Quote: Originally Posted by sweetpea
	nice vids Kiwi. Glad to know the results of the other systems in the same setup.

Didn't you lose a large scale gas model to this XPS system, early on? If I recall correctly, it was blamed on the stub transmitter antenna, which everybody said was not going to work, but Jim Drew maintained was going to be fine, due to some Magical Sperical Technology? And then he changed the TX antenna to the same type every other company uses?
Did your plane get replaced by XPS due to this design issue?

[sweetpea]

Facts......I did lose a plane early on. I cannot say that it was 100% XPS at fault. Sorry but I don't know that it was. It is suspected but not confirmed even to this day. It was never blamed on the stub antenna by anyone.

XPS came out while they were already in town and inspected the field and the other Vegas field. It was noted that the 2.4 spectrum had alot of noise on it at both fields. This was early on for even Spektrum systems so there was not alot of knowledge out there yet. They also came and inspected the install on my crashed plane. They also took my XPS gear back for testing and sent me new XPS gear even after it was determined that mine was not faulty.

Within a few weeks a new antenna was introduced for these high noise areas. Many users were still using the smaller antenna with no problems at other fields. Future versions included the antenna as a standard feature.

My plane was not "replaced by XPS" as so many people think. I did purchase a new plane from Wildhare though.....I'm sure you can call Tom and ask him about who purchased it if you wish. I also told them I wouldn't fly XPS in my GS planes again until telemetry and satellites were available because I felt this gave me more redundancy. I still have XPS in some of my smaller planes though.

And unlike everyone else--- I did not ask/demand XPS to replace my plane either as this is a hobby with risk. Even if I could prove XPS was to fault I still wouldn't demand more than my money back for the XPS components. You put a plane in the air and you risk it.....its very simple. Too many variables to hold one thing to blame. And I'm not the NTSB and I cannot recreate the exact problem since I don't have a black box on my planes that states exactly what every componant was doing at the time of the crash.


I'm not a "fanboy" of any company. I fly what I want regardless of what people think. I fly what makes me happy. I still believe that XPS has the greatest possibility for the future if all the items are ever released. With the current results that Kiwi posted it is good to see that Fasst and Spektrum surpase XPS in one situation. That should push XPS to hurry their butts up and make the upgrades available....competition is a wonderful thing and keeps prices low

Now what would be interesting is for the tests to include some more items.........when telemetry is available and the hopping code change I'd like to look at the test again with those to see what is going on. Then use Spektrum and the data logger to see what it sees.

Giving us all even more data as to what is going on in the 2.4 spectrum.

[Cherokee Jim]

Hey Sweetpea,

I agree with your thinking! I am conducting my own test out in the field and not on a bench. I have been in RC for more than 40 years and electronics just as long. So far in my test I have not seen the problems some are having with XPS or Spektrum. My test are on going. I don't try to Jam the entire band, the input of any radio can be overpowered, with enough power I can take a 72MHz system and Jam your 2.4GHz system - how? Will enough power can feed the circuit at any point in the circuit, just bypassing the front end.

What should be of much more concern to all is the Battery/Power Distribution problems --- much much more of a problem.

So far I consider the Spektrum and XPS to equal in reliability, I don't have a Futaba Radio.

I am trying to get confirmation but I hear the AMA has done or has had done test on the XPS, Spektrum, and the Futaba Systems and Futaba came in last! There is more to a reliable radio than just Frequency Hopping. Need to find that report.

For all of the Radio systems out there we want to do whatever possible to make them reliable - the choice among radios usually boils down to how one like the look and feel and their programing, what servos are offered, their service, etc.

Lawyers! Thats just what we need - Shysters hanging out at the flying field Ready and More than willing to purse a law suite at the drop of a hat. Did you ever wonder how Japan survives with only 1% Lawyers per Capita as the USA has?

So folks don't sit around and take someone else's word for something, get out and do the experiments yourselves.

2.4 GHz Spread Spectrum systems are new and evolving, techniques will change, it has with every system that has ever come out.

Happy Flying,
Cherokee Jim Mahoney

[Chris F]

Kiwi,

Thanks again for your work. So far it is the only testing done on these systems made public from the same source (to my knowledge). Xjet and yourself have also bought many members from other forums here to FG for the first time and it is by far the most unbiased and uncorrupted site to gather information on 2.4GHz systems. Thanks to the guy's here at FG for keeping it that way. This is the place I go to keep up with 2.4 stuff.

Well done all of you

[Simpleton]

Wonder if Kiwi is near the volcano that went off in Chile today? Chile is a looong country, plenty of places to be that aren't by a volcano I guess.

[Woketman]

Sweetpea said "Even if I could prove XPS was to fault I still wouldn't demand more than my money back for the XPS components."

Are you serious? If I could prove I'd lost a plane due to XPS's short comings, you d_mn right I'd ask for the $$$ to repair it. They'd say no (cause JD will never admit there is EVER a problem with XPS now), but I'd still ask!!!

[klhoard]

	Quote: Originally Posted by Cherokee Jim
	. . <snip>. . I am trying to get confirmation but I hear the AMA has done or has had done test on the XPS, Spektrum, and the Futaba Systems and Futaba came in last! . . <snip>. .

.
.
Now there is the type of factual, properly researched information I come here for!!!
.
.

[sweetpea]

	Quote: Originally Posted by Woketman
	Sweetpea said "Even if I could prove XPS was to fault I still wouldn't demand more than my money back for the XPS components." Are you serious? If I could prove I'd lost a plane due to XPS's short comings, you d_mn right I'd ask for the $$$ to repair it. They'd say no (cause JD will never admit there is EVER a problem with XPS now), but I'd still ask!!!

The reason why I wouldn't ask..........

XPS nor any other radio manufacturer states what type of plane, servo, motor, battery etc you use. Should they be liable for someone that chose to spend the max amount of money on every item? What if everything you put in the plane was used already from another plane? Now you also get into depreciation. How do you figure that in? Once a package has been opened the item is worth significantly less. Too many variables to expect any company to pay top dollar.

If you can't afford to lose your plane due to your own fault, someone elses fault (i.e. midair/shootdown etc) or a manufacturer defect or fault then find another hobby or fly smaller, less expensive planes.

I've lost 2 planes to a JR rx........never asked them for any money. I only asked them to replace the RX (which they never did as they couldn't find anything wrong with it). So I took a hammer to it. I'm still out the 2 planes and the RX but you don't see me bashing JR all day long.......I still fly JR

[Cherokee Jim]

Hello All,

" Now there is the type of factual, properly researched information I come here for!!! "

Once I or anyone else can find conformation of this report! Anyone heard anything?

In any case I will continue doing my own test until I am satisfied with the results - after all its my helicopter on the line, so I have to be satisfied that my setup, adjustment, and Equipment is up to par.

Happy Flying,
Cherokee Jim

[Cherokee Jim]

Hello All,

Over the past 40 or more years I don't think I have ever heard of a radio manufacture replacing someone's plane or helicopter due to a failure of their radio - maybe for a sponsored pilot.

Has anyone ever heard of this happening?

Happy Flying,
Cherokee Jim

[Simpleton]

Yeah, Futaba replaced one of the very first GUID interference loss planes.

And I doubt very seriously, based on the tests we've seen here, that XPS is better than Futaba or Spektrum in any type of test

[zoomer260]

Ouch !! My eyes hurt. Can you replace my eyes ? I'll even factor in depreciation !!

However I do agree with your post.