Kiwi's XPS test results are up.

[adjonym]

I was soooo close to buying the XPS system, but fortunately I ran into the threads about the hopping issue. The fact that I allmost bought the system is why I feel like I can post this reply.
Being a technician the only thing I can say about the XPS company responses is "WOW". They designed a system that was supposed to hop between channels if possible. The only problem is that they have no idea on how they made it hop, or under what circumstances, or even have a clue on WHY it would hop.
(Not exact quote "We do our testing in the real world, not in the shop"end not exact quote)

Anyone with ANY knowledge about tech or science knows that a result that can not be reproduced within a controlled environment is false, PERIOD.
Statements like "We test in the field" is just wrong on so many levels. In order to design a system that will change channels if needed you NEED TO KNOW HOW YOU IMPLEMENTED THAT INTO THE SYSTEM! And if you know how you implemented it into the system, you KNOW what parameters are required to reproduce it.

From the XPS responses you can only tell that they have no idea on how it would work. If they knew, all they would have to do to make all these threads stop, is simply to tell how it works, and how to reproduce it. All they are saying is that it works in the field, but it's impossible to show it in testings(OMG). It must be based on a randomizer, and it only works when the internal camera clearly shows that you are flying, and not testing the system inside.
XPS Code
$secret_xps_factor = randomize(1 to infinity);
If ($camera_outside == true) and $sunshine == true {
$rand = randomize (1 to 16)
if ($rand == $secret_xps_factor){
jump_channel
}
}

I guess the simple explanation for them not saying HOW is that they are simply lying.
If I would have bought the XPS system(and again, i was sooo close to doing just that) I would have sued them for fraud.

Selling a system that are not doing what it claims is fraud, simple as that.


It's sad though, since I allways like it when new small companys comes up with something new, and taking the fight with the "big ones". I always want them to succeed, since it helps us as customers, both tech-wise and price-wise(competition is good).
It's sad though, when it all ends up in a hoax, and a fraud.(XPS works, no doubt about that, but it's not working AS ADVERTISED).

[ben_beyer]

I'm with Kiwi, two antennaes and frequencies are better than one. If I go back to 2.4, I will only use a Spektrum or FASST system. And that's all I will recommend to anyone.

And as far as the bench test not being valid, well, if it can't pass a test in a controlled environment, how can it pass in the real world?

The plane was what, 10 meters away? Either way it's suppossed to change and it didn't.

[gareth.ky]

How do those 2.4Ghz cameras get licensed? They are not supposed to cause interference if they can detect traffic on their channel.

At least one thing the XPS dude is saying is true. If they source of interference is near the Rx its going to be worse than if its at some other location.

Since WiFi stations are stuck on the ground it seems that our only real problem would be Radar and 2.4Ghz video in other aircraft.

[klhoard]

	Quote: Originally Posted by Kiwi
	. . .<snip>. . I do not have the devices to totally swamp the entire 2.4 Ghz spectrum and see no real reason to go and procure such a device. . . .<snip>. .

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What about the readily available cell phone jammers? I imagine that the guys who get a thrill out of shutting down strangers cell phones in public will get a bigger thrill going to fly-ins.
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[Simpleton]

	Quote: Originally Posted by klhoard
	. . What about the readily available cell phone jammers? I imagine that the guys who get a thrill out of shutting down strangers cell phones in public will get a bigger thrill going to fly-ins. . .

Since cellular phones don't operate on 2.4Ghz in the US, it shouldn't be much of a problem.

http://en.wikipedia.org/wiki/Cellular_frequencies

[xed]

	Quote: Originally Posted by zoomer260
	I find this very interesting ! It never occured to me to fly a Transmitter below 9.6 volts. I always gave it a bump with a field charger. Is this not needed ? What is the voltage that most get nervous with ?

Why risk it, its not worth it... Fly at full charge, it takes no time at all to recharge the batteries for a new flying day.

[Simpleton]

	Quote: Originally Posted by gareth.ky
	How do those 2.4Ghz cameras get licensed? They are not supposed to cause interference if they can detect traffic on their channel.

Many of them aren't. Power output of these video cameras is limited to just a few hundred milliwatts in the US, any more than that and you need an amatuer radio license. Trouble is, you can buy a much more powerful unit off Ebay, a couple of watts, and use it. Nobody checks the power output or licenses at the field, and those powerful units aren't known for having the cleanest signal. On top of that, anything operating on 2.4Ghz has to accept any interference on its frequency, that's why you need to hop (or have a secondary frequency in parallel). I'd ask to see the specs on any video system somebody shows up with, and their Ham license if over the power limit (I think it's 200 mw, but I'm not sure. A visit to reputable US-based video dealers would probably show what they'd sell to unlicensed users).

[klhoard]

	Quote: Originally Posted by Simpleton
	Since cellular phones don't operate on 2.4Ghz in the US, it shouldn't be much of a problem. http://en.wikipedia.org/wiki/Cellular_frequencies

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That's good to know, let's just hope that these guys buy the right jammers!!
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[Julez]

	Quote: Originally Posted by xed
	Why risk it, its not worth it... Fly at full charge, it takes no time at all to recharge the batteries for a new flying day.

Well, the Fasst stuff I have seen so far has a 5v regulator on it. As long as you apply at least 6V from outside, everything is ok. As the transmitter computers do not change all of a sudden just because someone put a Fasst module somewhere near it, we can be safe to assume that it is no problem to handle recharging like we did the decades before.
Meanwhile, some swiss guys got over 2.3 miles with the Fasst system.

Sorry for OT.

[Simpleton]

	Quote: Originally Posted by klhoard
	. . That's good to know, let's just hope that these guys buy the right jammers!! . .

Well, they can buy 72Mhz jammers at any hobby shop.

On the other hand, all you'd need is a 700 watt microwave oven, take the case off (or leave the door off for a nifty directional antenna), plug it into an inverter, and swamp the 2.4Ghz band.

[klhoard]

	Quote: Originally Posted by Simpleton
	Well, they can buy 72Mhz jammers at any hobby shop. On the other hand, all you'd need is a 700 watt microwave oven, take the case off (or leave the door off for a nifty directional antenna), plug it into an inverter, and swamp the 2.4Ghz band.

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Good point about the 72Mhz jammer. . . . .
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However, I think a guy would look awful suspicious showing up to the field with a mangled microwave oven and an extension cord!!!
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[cptsnoopy]

Thank you Kiwi for responding. I asked the question as it is the very basis of the hopping feature. If the XPS continues to operate normally during your tests then that would invalidate everything you have shown on your video. Since I own quite a few XPS receivers it is still the biggest question in my mind. Will the system hop if it is being interfered with to the point of degrading function if there is a clear (or usable) channel nearby?

Again, thank you for your efforts. They are most definitely pointed in the right direction.

Charlie