Xtreme Power Systems

[hoot]

Looks like the Universal Module slated to be available end of April is no longer available.

[flymo]

Many orders received shipping emails with tracking numbers on Thursday (5/3). So I guess they should be received Sat-Mon.
It seems XPS delayed shipments until they updated the antenna on the Tx module.

A little communication through their website might have been a good idea

[cricket]

I offered a dispute with Paypal and I get a tracking number in about 1 hour. I am not the happiest customer as of yet.

[tppjr]

Looks like the 6 ch RX has been pulled from the website?

Anyone in the know????

Thomas

[flymo]

Transmitter modules now have two antennas!
Nice that the big one unscrews though.

[RCHeliJim]

Transmitter modules now have two antennas!
Nice that the big one unscrews though.


Thats actually a misconception. The old antenna "nub" is disconnected to use the screw on unit - you cant use both or either. JimDrew did say that you can special order the one with the old nub antenna only. If you get one with the screw on antenna - that will be the only antenna working. The plastic nub is just that, a plastic nub with no wire in it on the new ones. Figured I would post this in case someone decides to fly with the large antenna unscrewed - they would essentially have no antenna!!

[Motions]

I was just about to ask that very question. So can the nub be removed to fit a carrying case better?

Here's a close shot of the new antenna.

[DavidH]

Just my preference. But I think it would have been better to have the antenna mount on top like the Spektrum modules are going to be. And run a wire from the module to the antenna. Or at least put a guard on the antenna for it to rest against when laying the transmitter down like Futaba is doing.
From the picture looks like the antenna just pushes on or screws onto a coax type connector.

David

[Motions]

Who knows, they'll probably hold the next shipment to do just that. :mrgreen:

[wingtip]

not a very thought out design... constantly removing and installing the antenna everytime you put back in your case isnt good, just as with removing the module constantly... just best left alone..
I to prefer the nub and flew one of these few weekends ago with one of our electric birds and had no problems at all with several other helis in the air at the same time...

[PaulH]

That has got to be the most bone-headed idea I have seen in a while. Transmitters have the handle on the back to also be used as a stand. Now the antenna sits behind that? Brilliant. I agree with David that Spektrum has the right idea here. Even Futaba is doing better by adding a guard.

If I were to order an XPS, I would definitely get the nub antenna.

[DavidH]

If I were to order an XPS, I would definitely get the nub antenna.


Don't believe that is even an option now.

Attention customers!

We have changed our XtremeLink™ transmitter antennas. This new antenna allows flawless use in high noise environments. Customers who have already received their system have the option of returning it for a FREE upgrade! This upgrade is not required, but it is recommended if you fly in an area with exceptionally high noise from 2.4GHz devices.



Don't guess the little orb antenna was all it suppose to be. The customer beta testing must have revealed a problem with it.

David

[kgfly]

JD said that it would be an option to order a unit with just the nub antenna but it is not clear how long that option would remain available, possibly only until they get new plastic made without the dome.

The nub antenna worked (works) fine in most conditions. Problems were observed with sluggish response (a sign of high packet loss) at a Vegas event. Spectrum analyser traces show the noise level at that site to be at least an order of magnitude worse than anywhere else XPS had ever come across, approximately 20,000 times worse (-43dB vs -93dB) than their normal "high noise" test environment and very high in absolute terms.

http://www.rcgroups.com/forums/showpost.php?p=7401671&postcount=565



When tested at that same site the new antenna performed well and eliminated the packet loss problem. Hence their decision to standardise on the new, less convenient, antenna. For most users at most locations, the likelihood is that the old antenna would have worked perfectly well, as it is already for the hundreds of users that got the first batch of units at Toledo.

[spork]

Kenneth,

In your opinion could the signal be carried 6 or 8" on a piece of coax to locate the antenna remotely (where the normal TX antenna is)?

[kgfly]

Rick,

My opinion isn't worth more than anyone else's, and XPS have refused to respond to this very question so far, but in theoryI don't see why not. The original antenna required a fixed relationship with the PCB but AFAIK these stock WiFi-style dipole antennae do not. You would have to be certain to get the right kind of coax, I am not sure that the 50ohm or 75ohm stuff used for cable TV would be the right impedance match. The other problem is that every extra connection will introduce some loss and hence some reduction in range.

Until confirmation is received from XPS, I would think this would be OK for ParkFlyer or other relatively close range (eg. < 1,000ft or about 4% of the claimed range) use but otherwise would stick with the Mfr's configuration.

[kgfly]

Of course for those using the Universal module, which connects via the trainer port, you can make the cable to the trainer port as long as you like (within reason) and hence mount the module anywhere that is convenient (eg on top of your hat :mrgreen: ).

[kgfly]

OK, update on the remote antenna: http://www.rcgroups.com/forums/showpost.php?p=7406848&postcount=4316

So can the new Tx antenna be mounted remotely and if so, what kind of coax is required ?

Not legally. :)

[spork]

Thanks for the update. It seems my sloth and laziness have paid off yet again. I'll wait for this to all get sorted out before I make the plunge.

[Rogan]

The above statement says it all. This latency stuff is placebo. We are talking milliseconds here that over 90% of the humans can not tell a difference unless someone tells them it is different.

David

That's what I thought as well. But I wrote this little program to test that theory. At 100 msec of latency it becomes difficult to write your name.

http://www.helifreak.com/download.php?id=19778

I play online games, so I know that tiny differences in latency are noticeable. Good call on writing a program to prove it to the masses.

It is certainly unclear at this stage what's real and what's a form of placebo affect - they expect it to feel better so it does, even if it isn't!


The above statement says it all. This latency stuff is placebo. We are talking milliseconds here that over 90% of the humans can not tell a difference unless someone tells them it is different.

David
I think there are shades of grey here. Ask any 14mz/G3 owner whether they can feel a difference and they will assure you they can. Is that due to the 2048 resolution, the low latency, the fancy features or placebo ? Some of each I would guess.

Certainly a difference of a few milliseconds seems unlikely to be noticable and wishful thinking/placebo probably plays a big role. A difference of hundreds of milliseconds, is definitely detectable by almost anyone. A difference of tens of milliseconds, well I think a lot of variables will come into it, but there are many, many reports that suggest that it can be experienced. Perhaps the most credible are from expert pilots and for most it wouldn't matter, but then most folk never drive their Ferrari over 150km/h but most want one anyway :lol:

Another factor that is likely to matter is latency variation. Adapting to a fixed latency is fairly easy, but constantly varying latency where the variation is large compared to the average is probably more noticable than a fixed difference of the same magnitude. Hence one of the concerns with the 7c/9c/9z/14mz1024/T6EX which all have over 50ms/50% variation, far greater than any other system tested and IMO likely to be the detectable region, particularly when flown back-to-back with an alternate system having far lower variation.

Most of us won't get the chance to do a back-to-back comparison before making a purchasing decision so it's back to reading reports from others spanning from bench tests through to flight reports. All part of the fun :D

Have you got a link to the test results?

[TMoore]

Have you got a link to the test results?


It's been posted on RR for months and was just recently updated with the XPS results. I think I'll stick with my Stylus and wait for Sanwa to do 2.4 right.

TM

[kgfly]

Have you got a link to the test results?
The first post in the following thread is updated with new results as the author completes testing of new systems and combinations.
http://www.runryder.com/helicopter/t172571p1

[Rogan]

cheers. :)

*reads happily*

Mmm, I need to see data from the new Spekky modules. Looks like you add quite a lot of latency with the modules. No doubt Spektrum will be the same.

25ms for the integrated, to 60ms for the module is noticeable IMO. I'm biding my time.

[DavidH]

Jim Drew wrote:
kgfly wrote:
So can the new Tx antenna be mounted remotely and if so, what kind of coax is required ?


Not legally.



Wonder how Spektrum legally does it then?
Doesn't make sense to say it is not legal when another company is doing it.

David

[Motions]

I can only think he means you will void warranty by moving the ant. I doubt there's a patent on antenna placement on the module.

[DavidH]

I doubt so also. I am just guessing he is saying it is illegal due to maybe an FCC regulation. But hard to say since nothing said is ever very clear by that company.

I don't think there is a patent on any of it either. Don't think anything can be done if some other company decides to use a blue circuit board either LOL.

David