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2.4 Ghz Spread Spectrum Technology Discuss Spektrum, Futaba FASST, and all of the exciting 2.4 transmitter/receiver technology here!

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Old 02-06-2008, 03:50 PM   #481 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

Quote: Originally Posted by sweetpea
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The only thing the test is missing is comparison of FASST and Spektrum on the same test to verify that they are actually more robust and unaffected by the same situation.

Until that is done it is all speculation on our parts.

My opionion is that they will pass...but I'd like it to be 100% proven.
What would this test prove on FASST or Spektrum? Spektrum doesn't claim to hop and FASST hops constantly without interference.
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Old 02-06-2008, 04:01 PM   #482 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

Quote: Originally Posted by sweetpea
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The only thing the test is missing is comparison of FASST and Spektrum on the same test to verify that they are actually more robust and unaffected by the same situation.

Until that is done it is all speculation on our parts.

My opionion is that they will pass...but I'd like it to be 100% proven.
Well since I've been pretty much "on the money" throughout the XPS saga and my observations tend to be based on established physics and electronic theory, I'd be willing to put down good money that:

FASST will be largely unaffected by a gradual or sudden rise in a section of the 2.4GHz band of the kind that will "take out" an XPS system. Unless FASST uses an adaptive hopping algorithm (highly unlikely) it will simply show a gradual increase in latency as the strength/width of any interference increases. There will be no sudden loss of control -- even if 9/10ths of the band is unusable -- because it will continue to hop and regularly deliver data through the clear part. This makes it the most resilient of the technologies currently on offer.

Spektrum/JR will continue to operate virtually unaffected if one of its operating channels is clobbered by a signal strong enough to take out the XPS system. There may be an occasional hold or even a brief failsafe due to the effects of multi-pathing/shielding if no satellites are being used but the odds of a total failure of the RF link remain very low.

So which is best?

Well if you're the guy who thinks that FM is better than PCM because you can see the glitches before they get bad enough to cause a total loss of control you might be in favour of FASST, since the effects of very high noise levels across a large part of the band will be noticeable as a sluggishness in the response of your model.

In the same situation the JR/Spektrum user may be totally unaware that they've lost a channel and if/when the other channel gets hit all they'll know is that they got a lockout.

I'd be happy flying either Spektrum/JR or FASST -- but I've always said (right from the day it was launched) that I don't think XPS is a good idea for larger/dangerous models and I'm sticking with that.

The only fly in Futaba's ointment right now would appear to be Hobbico's "head in the sand" attitude to the field-reset GUID issue that Robbe in Europe has already acted on by issuing a recall.

If Hobbico don't do the same then (if I were in the USA) I don't think I'd spend money on FASST. I'd want a distributor who stood behind their product and put *my* interests ahead of their own butt-covering and bottom line considerations.
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Old 02-06-2008, 04:14 PM   #483 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

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What would this test prove on FASST or Spektrum? Spektrum doesn't claim to hop and FASST hops constantly without interference.
It would prove that hopping or having 2 freqs will bypass this specific test. Until we see that in practice it is all speculation by us.

Isn't that what everyone wants? To know one system is better than another.

Everyone is quick to bash one system but let the others slide. I bash all the systems. Prove to me they will/won't work in the same scenario. No more....."it theortically should work"


Radio waves are finicky things. Power, placement, freq, PRF etc etc etc all effect how things work.

I'd just like to see it proven that the other 2 work in the same condition.


Like Xjet's post above.....all valid points of why they should work. But why take those manufacturer words for it?

I think between this test and what Kiwi is going to do we will determine when each system works and doesn't work and how likely they will fail.
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Old 02-06-2008, 04:20 PM   #484 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

Well this puts the nail on the coffin for me. So much for giving a bargain basement operation the shadow of the doubt.

Now the only question is whether or not I'll make it three more weeks using XPS until FASST gets in at Tower!!!

I sold all of my 72 mhz stuff...what a bummer.
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Old 02-06-2008, 04:21 PM   #485 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

Good luck! I didn't fair so well...
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Old 02-06-2008, 04:23 PM   #486 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

Its close to a nail for me also.

Show the other 2 systems pass in the same test and it seals the deal. And I think most others would think the same.

If the others fail as well though.......?
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Old 02-06-2008, 04:25 PM   #487 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

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Like Xjet's post above.....all valid points of why they should work. But why take those manufacturer words for it?
Well one reason is that none of Spektrum/JR or Futaba's claims are in conflict with the basic laws of physics as XPS's have consistently done.

JD/XPS have blown *any* credibility they might have had as each of the outrageous claims made for XPS have been shown for what they are: either a significant lack of understanding of the technology they're using (not a good thing) or just outright lies.

Futaba are not immune to hyping ("we get it right first time" yeah-right!) but at least on a technical level they aren't blatant enough to suggest they're able to defy the laws of physics or electrical theory or have some "magical mystical" technology known only to them.

Nothing I've seen in the way of claims made by JR/Spectrum or Futaba rings alarm bells in the way that the XPS hype did. While they may have their own issues, I have no reason to doubt that the systems will function "as advertised".

You're right that only testing will *prove* this to be the case -- but I'm prepared to bet good money at this stage ;-)
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Old 02-06-2008, 04:28 PM   #488 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

Thanks Jon...I plan to break out my trainer and put away the gasser until Futaba's FASST stuff comes in..lol.
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Old 02-06-2008, 04:34 PM   #489 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

Agreed Xjet.....

I just want it proved that the other systems are more robust in this scenario. Not difficult to do...he just needs to get his hands on the units and time to do it.
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Old 02-06-2008, 05:34 PM   #490 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

41 pages?
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Old 02-06-2008, 05:47 PM   #491 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

Quote: Originally Posted by XJet
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I'll check this cheap Chinese 2.4GHz set and see what it does.

I'm sure you will!
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Old 02-06-2008, 06:02 PM   #492 (permalink)
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Default Re: Independent tests prove lack of frequency hopping with XPS

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41 pages?
Just think of it as a long term, informal, and highly anmimated Kaffe Klatch, Dave . .bunch of olde hens sitting around, eating pastries, drinking coffee, slandering, rumor mongering, arguing, and basically having the fun time women always do when they are not shopping but there are more than three in the same room.

After watching this thread for so long, I wonder. . are men and women REALLY so different???
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