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Oct 11, 2006, 10:27 AM
Proud to eat Kraut ;-)
Julez's Avatar
I've flown this plane to ~6000ft without problems.

I'm looking forward to installing Jim's system (if next spring no manufacturer offers a better one) and doing the test again.

As the failsave was set to idle, one can see that no glitch during the climb ocurred.

Regards,

Julez
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Oct 11, 2006, 11:11 AM
Team Futaba
Silent-AV8R's Avatar
All I can say is that I wish I had the eyes some of you guys have!!!I can hardly see a Cessna 172 at the far end of a 5,000 foot runway let alone a small model at several thousand feet!!!
Oct 11, 2006, 11:36 AM
Closed Account
Did someone forget to subtract the base altitude from the recorded altitude? We watch skydivers over our field, many of them six foot tall and we can barely see them fall out of the plane at their usual jump altitude of 1500 ft. There have been planes flown autonomously from our field as part of a Grumman project and a four foot Zagi at a programmed altitude of 800 ft. is barely visible.

The (IMHO) figures presented in the above posts constitute hogwash.
Oct 11, 2006, 11:53 AM
And You're Not
I generally quit flying my plane after I lose sight of it. If I have control out to as far as I can see, that's all the range I need, regardless of numerical measurements.
Oct 11, 2006, 11:57 AM
Dave Raines
Lemmiwinks's Avatar
Quote:
Originally Posted by ArestiMan
I'll be satisfied just to see it in a 150cc size aerobatic plane, a .90 size heli (preferably with CF frames), and a 3-meter or larger CF/glass glider. Once proven in those application (or similar) then the turbine guys can likely feel comfortable. Going to be hard to find a turbine guy willing to use his plane for testing.

And once again, I will not use one of these systems from ANYBODY, until it has been shown to be reliable in these types of applications.
I fly with two turbine pilots who are dying for a system like this to put in their turbines. If you don't like it, you dont have to buy one. I for one am tired waiting for the big boys to roll out new technology. I bet the management at these companies is filled with people with your poor attitude...
Oct 11, 2006, 12:13 PM
Team Futaba
Silent-AV8R's Avatar
Quote:
Originally Posted by Lemmiwinks
I fly with two turbine pilots who are dying for a system like this to put in their turbines. If you don't like it, you dont have to buy one. I for one am tired waiting for the big boys to roll out new technology. I bet the management at these companies is filled with people with your poor attitude...

Huh?? All I want to know is that it will work safely in the desired application. That's a "poor attitude" to you??

I too am dying for this technology. I just want to know that it is safe to use. Early testing indicates some potential problems, so let's not stick our heads in the sand and pretend everything is OK. XPS has made some interesting claims, but to date have only presented test demos in a foamy and mid-sized electric.

So based on that you'd happily strap it into a turbine and go for it?? OK, as long as nobody else is jeopardized by your decision.

All I want from anybody selling one of these systems is evidence that they work as advertised in the applications they are intended for. This, as opposed to simply mindlessly accepting the unsubstantiated claims of a previously unknown vendor. OK then.

XPS, Spektrum, Horizon, JR, Futaba, and whomever else wants to sell this type of system needs to be able to demonstrate that the thing works as advertised and not rely on the modeling public to find out if it doesn't.
Oct 11, 2006, 12:16 PM
Proud to eat Kraut ;-)
Julez's Avatar
Quote:
Originally Posted by Ron Williams
Did someone forget to subtract the base altitude from the recorded altitude? []
The (IMHO) figures presented in the above posts constitute hogwash.
Well, our airfield is about 50m above zero. However, the Zlog needs a minute or two to calibrate itself to ground pressure after switching on. I carefully watched the "calibration done" LED before starting the engine.

The first flight only reached 1500m. My buddy who owns the Zlog beleived in a malfunction, so I had to try again. This time I put a little more efford in it.

My brother owns a Garmin GPS handheld system that we strapped on the plane some days later when I was up taking some photos. It showed a peak altitude of something 1500m.

So I believe the readings from the Zlog are real.

Regards,

Julez
Oct 11, 2006, 01:03 PM
Registered User
Jon Koppisch's Avatar
I've seen a 40 sz trainer flown over 5,000 ft. Our club president (in WV) strapped a gps unit on his trainer, checked the alt (it was around 300ft), set it for record mode and went as high as he could. Brought the trainer back down and landed and there was over 5,300 ft high recorded.
Oct 11, 2006, 01:30 PM
12th Pursuit Squadron
TheAeronut's Avatar
Some people seem to not believe that this system works at all unless 'it is tested in an airplane EXACTLY IDENTICAL to MY AIRPLANE' including equipment installation and whatever construction foibles that they may have. They and others seem to demand a multi-year, multi-million dollar hard data test program to be performed and published before anyone outside of the development team is exposed to this technology.

Get a life, sit back and wait a year or three after product release for those who are more than happy to fly these alpha design - never been tested or flown vaporware marketing hype imaginary dreams. Quit bitching at everybody for your total inability to believe that this system might actually work and the possibility that it has been tested in more than just a foamy and a little bitty quarter scale electric plane.

My eyes are maybe average in terms of acuity with corrective lenses. If I am wearing my glasses, I can readily see a Zagi at 800 feet. OK, I admit that I might be challenged to actually fly a small foamy at 1800 feet, but I could at least see it - it would not disappear all together.

While I do take Marketing Hype with a large grain of salt, I have seen evidence of much more than just Marketing Hype here. No, I do not believe that this system is Perfect or Infallable, nor that it will never experience bad packets. I do believe that the incidence of bad packets will be small and readily flown through.

One small observation. Even if an airplane or helicopter were hovering ABSOLUTELY RIGIDLY IMMOBILE IN PLACE exactly in a reception null, I seriously doubt that the pilot would be able to maintain that same rigid immobility. I have never see a pilot who does not move at all while flying. The transmitter will certainly move and move the null away from that curiously rigidly immobile aircraft or helicopter. I firmly believe that the quality and security of the RF link of this and other SS systems is likely at least an order of magnitude better than our existing and apparently acceptable 72 MHz systems.

Please note that there are no names mentioned here, but several people have taken this attitude over the life of theses threads. This rant is not meant as an insult, just as a notice that some (probably many) of us get tired of non-constructive negativity and bitching.

J.P.
Oct 11, 2006, 01:54 PM
Happy FPV flyer
Kilrah's Avatar
Oh, now that's interesting... I should really come here more often!

OK, I'm getting 2 sets ASAP...
Really long for some reliable stuff.. let's have some hope. Now one thing, how does the receiver cope with a fixed freq 2.4GHz TX that spits out just a couple of centimeters apart?

Now to how to see a plane at that distance... seems hard to me. I've seen friends doing some aerotow with a 2.5m plane and 4m glider. They went up to 1000m (live telemetry installed), at this point it was very hard to see the 2 aircraft..

I've done 1.8km distance but flying FPV... no problem in that case if the gear cooperates. That was the radio's limit BTW, the plane was starting to fly a bit too erratically...
Last edited by Kilrah; Oct 11, 2006 at 02:00 PM.
Oct 11, 2006, 01:59 PM
And You're Not
Quote:
Originally Posted by TheAeronut
One small observation. Even if an airplane or helicopter were hovering ABSOLUTELY RIGIDLY IMMOBILE IN PLACE exactly in a reception null, I seriously doubt that the pilot would be able to maintain that same rigid immobility. I have never see a pilot who does not move at all while flying. The transmitter will certainly move and move the null away from that curiously rigidly immobile aircraft or helicopter. I firmly believe that the quality and security of the RF link of this and other SS systems is likely at least an order of magnitude better than our existing and apparently acceptable 72 MHz systems.

J.P.
Interesting post, J.P. Echos some of what I said Here

Quote:
Originally Posted by Jeffery
Yeah, you might be able to produce a null in the system if it is perfectly stationary on the bench. Luckily, most people in the real world don't fly benches. Even a heli or 3D plane hovering will not be as absolutely stationary as a bench. That's the real world vs theoretical difference I'm talking about. Sure, some guy might hover his heli long enough to get a null, as soon as it deviated it should clear the null area and resume operation. Not sure your bench would replicate that, not sure it would even be an issue to the heli guy. All I hear is that it's violating the pesky laws of physics, I say it's obeying the laws of physics but it might, just might, be good enough in real world operation.
and Here

Quote:
Originally Posted by Jeffery
It's amazing how many people who fly ignition gas engines use PCM to get away from the glitching they experience when using PPM. I say if you eliminate the interference, you don't need PCM, but many, many people go to PCM for just such a scenario.

Now on the bench, you'd say there was interference and it needed to be addressed. Real world, they fly some very expensive airplanes quite sucessfully on PCM that would glitch were they on PPM.

So the system is not 100% per the engineer, yet the end users are proving it just fine in real world applications. Every day.

Just like this system. I'm sure there will be engineers who can give an absolute null pattern down to the 1/10th of a degree on a bench while the end users will be flying. Or maybe not flying, that's where the additional testing will come into play.

I'm just saying that literally thousands of end users are relying on PCM to mask deficiencies in their system that would be glaringly obvious if PPM were used. This system may indeed show similar deficiencies in rigorous lab testing that just won't matter to real world end users.
Oct 11, 2006, 02:55 PM
The module transmits at 100mW. This is greater than the 25mW (60/2.4) FCC rf exposure limit.

The FCC rf exposure limit in mW is 60/f in GHz. (60/2.4 = 25).

To be FCC legal, Extreme must sperate the antenna 20cm from the human body. It looks like they violate this requirement.
Oct 11, 2006, 02:59 PM
Team Futaba
Silent-AV8R's Avatar
Quote:
Originally Posted by TheAeronut
Some people seem to not believe that this system works at all unless 'it is tested in an airplane EXACTLY IDENTICAL to MY AIRPLANE'

J.P.
You are misstating my position. What I am saying is that this system works, but so far all it has been shown to work in are a foamy and an electric plane. There is a wide variety of planes out there and these systems, regardless of the maker, will need to demonstrate that they work reliably in as many different types of planes as possible before we can use them with confidence.

As far as negativity and bitching, many others of us get weary of unquestioning acceptance of anything a vendor says.
Oct 11, 2006, 03:02 PM
Registered User
I'd like to see not only othe planes, but more than one system on 2.4 running in the same area.
Oct 11, 2006, 03:23 PM
Foam abuser!
crxmanpat's Avatar
Quote:
Originally Posted by ArestiMan
Huh?? All I want to know is that it will work safely in the desired application. That's a "poor attitude" to you??
I see you have conveniently decided not to answer my question of your motivation. If you say simply that you're questioning this system's ability to perform, I say "show me where". All I've seen from you so far is a "poor attitude".

Have you read the entire thread? I mean all of it. I have. Numerous times Jim has stated that much testing has been done, and there is still more to come before the system is made available for purchase.

But, isn't it true in all cases of new products hitting the market, that thorough testing in every real world scenario is not possible until people buy the products themselves? Take cars for instance. A manufacturer puts out a totally new design. Rarely is it seen that the car is totally flawless, and is in need of modification.

I'm sure that as Jim gets more testing done, he'll be more than happy to reveal his results with us.

Pat


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