Independent tests prove lack of frequency hopping with XPS

[Woketman]

	Quote: Originally Posted by sweetpea
	Xjet........there you are totally wrong. I myself have written tons of code for products since I started in computers years and years ago. Maybe not quite a million but it is up there. a million lines of code is not that big a deal actually and wouldn't take a lifetime to create. Video games are twice that. Keep the thread on topic please and keep your dislike of JD out of this. Remember XPS is not just JD but Scott as well. JD just happens to be the spokesperson online

I disagree!! I would like to thank XJet for continuosly re-hashing all of the JD hype & BS so that newbies will understand the lies that JD has spouted for the last few years.

Please XJet, NEVER let up. Stay on the attack as many of us appreciate everything that you have done to open our eyes. I just wish mine had been opened before I wated my $$$!

[XJet]

	Quote: Originally Posted by sweetpea
	Xjet........there you are totally wrong.

Nope, I'm 100% right!

I've been in the software industry for over 30 years and I often hear *programmers* say "I can write faster than that" -- until you sit down with them and show them how very few lines they actually write per day when amortized across the entire development cycle.

We're not talking about sitting down in the morning and delivering 500 lines of code by lunchtime - anyone can do that - but it's *not* the whole story.

Once you include the initial program specification, systems analysis, structuring, coding, testing, debugging, etc, 5-7 LOC per hour is a *very* reasonable figure.

	Quote:
	I myself have written tons of code for products since I started in computers years and years ago. Maybe not quite a million but it is up there.

Yes, but you're not including the hours you spent doing the SA, testing, debugging, documenting etc are you? You're thinking "I sat down on Monday and by the end of the day I'd written x00 lines of code -- but was that code totally bug-free, did you include all the prelimary work? Was it properly documented?

	Quote:
	a million lines of code is not that big a deal actually and wouldn't take a lifetime to create. Video games are twice that. Keep the thread on topic please and keep your dislike of JD out of this.

It's nothing to do with my "dislike of JD" it all refers to the man's credibility and therefore the veracity of his claims in respect to the XPS system -- something which I think even you will agree *IS* important.

You are right, many programmers (including me) have cut, tested, debugged and documented a million lines of code throughout their career -- bug JD is claiming millionS of lines -- that's more than a million.

	Quote:
	Remember XPS is not just JD but Scott as well. JD just happens to be the spokesperson online

But JD claimed he'd *personally* cut "millions of lines of code".

What it boils down to is that JD continues to spout BS and that's got to be a worry for anyone considering XPS as a product.

A sound product doesn't need BS to sell it. Just as a good programmer doesn't need to boast about unrealistic productivity or degrees they don't actually have.

It's very seldom that you get top-quality lubricants made from snake-oil.

[capgains]

Yep this is a whole new level of obsession.

[Panzlflyer]

I think that word of mouth has taken care of most Xps systems except for a few poor guys who dont do any research.
"But wait if you order in the next 10 minutes We'll send you 2"
I have yet to see one our way.

[Pale Rider]

	Quote: Originally Posted by Panzlflyer
	I think that word of mouth has taken care of most Xps systems except for a few poor guys who dont do any research.

BUT--according to JD his user base is in the "tens of thousands"

[Simpleton]

	Quote: Originally Posted by capgains
	Yep this is a whole new level of obsession.

There are more than a few posters in these XPS threads who have never posted in *any* other threads here.

	Quote: Originally Posted by Panzlflyer
	I think that word of mouth has taken care of most Xps systems except for a few poor guys who dont do any research.

And ironically, the only place they'll ever find that info is on the web...the same only place that XPS advertises (in the US, anyway).

[skubacb]

- Kiwi, at least you understand the limitations of your testing as some others do not. It was not a test to see if XPS would hop since you did not have the parameters under which it would hop.

It probably shows that the XPS RX is more sensitive, i.e. gathering in more of the signal and noise.

Blanket statements as to what this means is objectionable and unreasonable since there is no data to come to further conclusions.

- Spherical coverage is just that. We are not talking about the antenna pattern which indeed does seem to have a dimple. At the first AMA convention where JD talked about the system he stated that there was a dimple. I worked antenna patterns and coverage in my AF operational testing and a dimple is not necessarily a dead spot. The RX may allow a DB level low enough that you do indeed have spherical reception. Thus is is NOT at all magical.

JD is NOT the person that started this line of BS about an isotropic antenna. Someone else took the advertising and decided to call it isotropic and thus decry the XPS system. For most intents and purposes all our planes systems have spherical coverage. Otherwise we would all have aircraft that would fail to respond in depending on the a/c angle to us. No not magical at all, just advertising.

- I believe my number of successful flights is important considering that some people have posted that they could never get the system to link and that it was an XPS problem. I have had 21 RXs link exact according to the instructions. Multiple times to two different TX modules. As an experiment I took a trainer up. Failsafes were set on all channels to make the a/c fail to idle and a gentle descending left turn (try that with Fasst or Spectrum). Once the trainer was quite high, I turned off the TX. The trainer went into idle and a gentle left turn. I then turned the TX back on and as soon as the Futatba 9CAP beeped that it was on, I had control again.

Is XPS bullet proof. I very seriously doubt it. But I find it no worse than my Fasst or Spectrum systems. Actually, for flights flown without problems it has been better than Spectrum.

[BaldEagel]

	Quote: Originally Posted by skubacb
	- Kiwi, at least you understand the limitations of your testing as some others do not. It was not a test to see if XPS would hop since you did not have the parameters under which it would hop. - I believe my number of successful flights is important considering that some people have posted that they could never get the system to link and that it was an XPS problem. I have had 21 RXs link exact according to the instructions. Is XPS bullet proof. I very seriously doubt it. But I find it no worse than my Fasst or Spectrum systems. Actually, for flights flown without problems it has been better than Spectrum.

The XPS system in my plane in the air did not hop, just locked out on four occastions in two places of line of site of the transmision towers.

I think what is important is that one unsuccesful flight is enough, on the ground the system did all it was supposed to do by linking in accordance with the instructions, it was just in the air it did not work.

My FASST and Spektrum systems and others on my flying site, have worked without fault, glitch or lock out since day one, they I consider to be as bullet proof as you can get, is XPS bullet proof NO definatly not.

As a reminder to those reading this, the Graupner IFS system in Europe is the XPS system form the US.

Mike

[Pale Rider]

	Quote: Originally Posted by skubacb
	Actually, for flights flown without problems it has been better than Spectrum.

Thats an interesting comment. Can you show the data that would corroborate this ?

[Simpleton]

	Quote: Originally Posted by Pale Rider
	Thats an interesting comment. Can you show the data that would corroborate this ?

I think he was talking about his own experiences. I don't know about him, but I don't log every glitch or twitch I ever had so I can have data to back up my glitches and twitches. YMMV.

[Pale Rider]

	Quote: Originally Posted by Simpleton
	I think he was talking about his own experiences. I don't know about him, but I don't log every glitch or twitch I ever had so I can have data to back up my glitches and twitches. YMMV.

Ok--I re-read it and saw he was speaking of his own flights..

[Toumal]

	Quote: Originally Posted by XJet
	Nope, I'm 100% right! I've been in the software industry for over 30 years and I often hear *programmers* say "I can write faster than that" -- until you sit down with them and show them how very few lines they actually write per day when amortized across the entire development cycle.

I'm a full-time software developer myself, developing ground systems for air traffic control. IMHO XJet is right when he says that millions of lines of code sounds very exaggerated, and that writing lots of code is no indicator for quality - in fact, quite the contrary. Software developers who believe that are often seen coding away from day one, whereas the experienced developer starts with his design while drinking a cup of coffee. Most often, he will be the last to have the first version running, but at the end he'll be the first to have it passing all tests.

	Quote: Originally Posted by skubacb
	Spherical coverage is just that. We are not talking about the antenna pattern which indeed does seem to have a dimple. At the first AMA convention where JD talked about the system he stated that there was a dimple. I worked antenna patterns and coverage in my AF operational testing and a dimple is not necessarily a dead spot. The RX may allow a DB level low enough that you do indeed have spherical reception. Thus is is NOT at all magical.

Oh certainly, you will still receive something. But the question is how much.
This is the pattern of a 1.5GHz monopole antenna:





I'd say the dimple is rather significant, and it only gets worse with higher frequencies.

Also, at the end of the day it doesn't matter if it's "just marketing". If a car maker claims that his airbags are enough to eliminate the risk of a frontal crash at 40mph, and it turns out that parts of the engine compartment cut off your legs at a crash test, it's still a lie.

The Graupner website says this: "Approximately spherical RF radiation pattern; no multi-element aerials required"

Well, there's a joke in mathematics: "In first approximation, a cow is a spherical object that emits equal amounts of milk in all directions."