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Old 07-19-2007, 06:56 PM   #1
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Cool 2.4 GHz - A Broad Market Review

2.4 GHz AIRCRAFT SYSTEMS
A BROAD MARKET REVIEW
by Ed Anderson
aeajr on the forums

This broad market review is provided to help prospective 2.4 GHz users understand what is going on in the market. As each of the 2.4 GHz brands uses a different communication standard, they are not compatible with each other. This mean that a decision to move into the 2.4 GHz is also a decision to use oneof these 2.4 GHz implementations. I am going to examine what factors might influence one's decision to go with one or the other.

It seems the 2.4 GHz airplane radio system market is growing fast. New flyers are adopting it quickly and existing pilots seem to be very interested in moving to this new environment for its promised safety and perhaps its faster response. Manufacturers are now incorporating 2.4 GHz into RTF models. In my opinion, 2.4 GHz is not the wave of the future, it is the wave of today.

If we look at the currently available players we see Futaba, Xtreme Power Systems, XPS, and Spektrum. JR is shipping 2.4 GHz systems based on the Spektrum standard, so I will group them with Spektrum.

If we look at forum buzz as a market indicator Spektrum/JR appears to be the dominant player with complete radio systems, announced transmitter modules for JR and Futaba and a wide selection of receivers. Spektrum has been shipping 2.4 GHz radio control systems for several years and has a large user base in airplane and RC cars and boats. Spektrum products are available from a variety of hobby stores and internet sites.

XPS started shipping in April 2007. They would seem to be a distant second with a broad selection of transmitter modules and a couple of receivers. They are sold from the XPS web site only as far as I can determine.

Futaba started shipping an entry level 6 channel transmitter/receiver combo around April as well. They have announced upgrade modules for Futaba module based transmitters but they have not started shipping as of this writing.

I am not going to focus on the specifics of their respective technologies except as to how it would impact a user. They all seem to be getting good reports so it appears they all work. While there are more problem reports on Spektrum, their installed base is huge compared to XPS or Futaba so you would expect to see more problem reports. I don't see this as a negative indicator and reports are that Spektrum is doing a good job with customer service.

Note that high carbon content fuselages and some metallic coverings have always been a problem as these can block radio signals. For 72 MHz, where the receiver antenna is around 40 inches, this has been something that can be managed as the antenna can easily be routed outside the plane. On 2.4 GHz systems the antennas are tiny. Users are trying a variety of methods to get around the carbon fuselage issue. If your planes don't have carbon or metal fuselages, this is not an issue, but if they do, be aware that it could interfere with the 2.4 GHz signal. Do some reading to see what is working and what is not. Make sure you do careful range checks before you fly to insure you have good signal and no dead zones where the signal is blocked.


XPS - Xtreme Power Systems
http://www.xtremepowersystems.net/

XPS chose to go after the larger plane and experienced flyer market first. They are only selling after market transmitter modules. They are not offering an XPS transmitter. So, their target market is upgrade modules for existing owners who have module based systems. This addresses the mid market to high end users and really does not address the entry level market at all.

XPS initial offering is based on 8-10 channel receivers and a receiver design that calls for a little more room in the plane than the other brands. If you are flying glow, gas, medium to larger electrics and gliders with large spaces in the fuselage, it seems that XPS has options for you. However if your transmitter is not module based, or if you are buying your first radio, you can't choose XPS. While XPS modules have more brand transmitter coverage than Spektrum, you have to buy someone else's midrange to high end transmitter first in order to adopt the XPS standard.

XPS has been more willing to share range specs than the others. They have a small 6 channel receiver coming that looks good, from a specs and a price point of view. The published specs say 1500 foot rated air range. That would be great for most planes under 60 inch wing spans which is a huge part of the market, especially the electric market. For planes larger than that, their larger receivers will probably fit and do a good job.

For most slope gliders under 2M, the bulk of the slope market, the 6 channel will probably be fine. For other gliders the XPS receivers could be a problem either for size or range. For hand launched gliders their new 6 channel may or may not fit and have enough range. For thermal duration gliders that are 1.7 M or larger the 6 channel probably does not have enough range. For these larger gliders, it remains to be seen if the 8 and 10 channel XPS receivers will fit in many of the narrow fuselages, but range does not appear to be an issue.

XPS seems to handle low voltage receiver pack or BEC issues better than Spektrum. Specs suggest that the XPS systems are faster to reboot if the pack has a momentary drop below a critical voltage level. This can occur if servos demand a lot of amperage causing a sag in the receiver pack or BEC voltage. I don't know how Futaba handles this.

XPS also promises 2 way telemetry in the future. That could be a nice plus for XPS users.

XPS uses a channel hopping approach to frequency management. They say that they can have over 100 simultaneous users. With XPS you are highly unlikely to get locked out due to the radio slots being all used up by XPS system users. Even at large events with a hundred or more pilots, some will be on XPS, some on other 2.4 GHz standards and some on 72 Mhz. Available channel space for XPS users should not be a problem.

If another major radio provider, like Hitec or Airtronics were to announce alignment with XPS that could be a big boost for XPS market share and acceptance across a broader range of users. You could then buy a transmitter that is XPS based. Or, if retailers were to sell new transmitters with XPS modules then you could buy a Hitec Optic 6 or a Futaba 9C, for example, with an XPS module rather than a 72 MHz channel module. It will be interesting to see what develops in the market.


SPEKTRUM
www.spektrumrc.com

Spektrum targeted the parkflyer and micro heli market first when they released their DX6. New RC pilots could buy a cost effective 6 channel computer radio with a good range of features as their first transmitters and have no frequency control issues to worry about. Reports suggest that this is the fastest growing part of the market and one that will readily adopt a new standard so this was a good starting point for building a new installed base. Once satisfied with the Spektrum system these new flyers would likely stay with the Spektrum standard. Based on forum buzz, the DX6 is still selling well as the price is holding up with little discounting being seen.

The follow on DX7 works with the 6 channel DX6 receiver so there is an upgrade path within the Spektrum label for those who want more channels and more features. Now that JR has adopted the Spektrum standard, you can buy a full range of transmitters that will work with Spektrum receivers.

If you are a new flyer, or if you are flying small planes or tight fuselages, Spektrum has a wide selection of receivers going from micro receivers to 9 channel multi-receiver offerings. With JR adopting the Spektrum standard and modules for Futaba coming out, Spektrum's base can expand even further. Spektrum has established itself as THE dominant standard in the 2.4 GHz airplane/heli market. They also have a major position in the RC car market. It is unlikely that Spektrum will be the only major standard, but it will certainly be one of the main standards.

Reports suggest that Spektrum's receivers are more vulnerable to low voltage pack problems as their receivers are comparatively slow to reboot and reacquire the transmitter signal. However, now that this is known, with proper planning this should not be a major issue as you should take it into account in your installation. While they have been resistant to releasing any numbers on receiver ranges, the user community has been active in establishing some acceptable ranges for their receivers. Seems Spektrum has been conservative in their marketing information and their receivers can be pushed out further than would have been initially suggested.

Spektrum's channel management approach limits their system to 40 simultaneous users. While this number seems large compared to typical pilot population at the field, as 2.4 GHz becomes the standard and frequency control starts to go away, will Spektrum users be locked out at large events? While you might only have 5 Spektrum pilots in the air at one time, you could easily have more than 40 Spektrum users at an event. If you have 40 Spektrum based transmitters turned on in the pits, will you be locked out from flying even as you approach the line? Again, we can expect that many pilots will be on other standards, but will this become an issue in the future? It is something to consider if you frequent large events.

FUTABA
www.futaba.com

What of Futaba? It is too soon to tell. There don't seem to be that many 6EX 2.4 GHz systems out there yet. Those who have them seem to report that they work well but many are dissatisfied with the features of the transmitter and the price for the features provided. However this does give Futaba an entry level system for new buyers, though more expensive than the Spektrum DX6. If you take the price of servos into account, it is about the price of the DX7 but with a vastly more limited feature set than the DX7.

We really can't rule Futaba out as they are a major force in the market. They are just a bit late and slow to get up to speed and their prices are higher than Spektrum or XPS for the features delivered. Futaba seems to be focused on Futaba customers at this time as they have made no announcements of modules for other brands. Once they get rolling, they may become a major player in this 2.4 GHz market. I am sure their technology is good, but will it be niche, like PCM, or will it become a market standard. Only time will tell. If Hitec, or someone, else were to adopt the Futaba standard that would be a huge boost for their market position. This is the dark horse player at this time.


A Personal Prospective

As an experienced flyer who already owns two module based transmitters, I like that XPS is available for just about anything including my Futaba 9C and my Hitec Prism 7X. If I go with the XPS standard and want to move to an EVO, Hitec, JR or something else in the future, my XPS receivers would work with those transmitters. The fast reboot of their receivers and the promise of two way communications between receiver and transmitter is very attractive.

I like that Spektrum has such a large user base, as there IS safety in numbers. However that could be a lock out issue looming for the future. And they don't have a module for my Hitec transmitter. They have full range as well as micro receivers so they have receivers for each of my planes. With JR on board, this standard is well established.

I fly a Futaba 9C but do not consider Futaba as one of my likely choices based on price, availability and the fact that I would be locked in to a Futaba brand for any transmitter upgrades. Futaba could become the PCM of the 2.4 GHz world, maybe better but brand specific. That does not interest me at this time.

If I was going to buy today, I would buy Spektrum based on the selection of receivers and the ability to fit their receivers in my planes. My electric planes tend to be small and light. Some of my gliders have really tight fuselages and I will need LOTS of range for the gliders. Spektrum has receivers that meet these size, and range specs.

Your needs will be different, but I hope this summary is useful in your choice. They all seem to work well enough to be considered for your next purchase. It is just a matter of what works best for you.

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Old 07-19-2007, 08:05 PM   #2
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Thanks for the very informative and un-biased review Ed!

~Aaron~
-It's not the size of the heli, it's how you fly it!
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Old 07-19-2007, 08:18 PM   #3
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{insert Forrest Gump voice} "Ed always had a way of sayin' things so I could understand them."

Ed,
Thanks for this extremely informative write-up.
I have been in the RC hobby for about a year now and I think I am close to out growing my Futaba 4-YF. I am sure this thread will help me be a better informed consumer once I cross over to the 2.4GHz standard.

John
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Old 07-19-2007, 09:03 PM   #4
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Glad you find this helpful. That was the goal.

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Old 07-19-2007, 09:16 PM   #5
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Nice writeup, Ed. I currently own two an XP6102-SPK (conversion) and a DX-6, plus about eight AR6000 receivers. So far I've been pretty happy with the Spektrum stuff, with the exception of the low voltage/BEC problem - I think the 2.4G receivers (all of them not just SPK) have more problems with low voltage than the older 72mhz did.

Personally, I think that the XPS stuff has the most potential. The fact that they're not tied to "old school" thinking helps quite a bit with innovation - the two-way communication potential is very exciting to me. They are apparently working on a couple complete systems - an 8-channel kit for about $200 and a 16-channel (!!!). When these come out I will be looking very seriously at selling off my Spektrum gear. Just imagine having a voltage monitor built into your TX, giving you realtime voltage on your pack... that right there would be enough to sell me on the system.

If they're able to pull it off, I know what I want for Christmas...
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Old 07-19-2007, 10:02 PM   #6
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Hello all, im new here and kindof new to the hobby, well i mean actually flying but am 42 and have went to many rc shows.
Anyway, i am an electronic tech hence my username.
Let me fill you in on something in ref to 2.4 ghz aka 2400mhz.

Do you remember your regular cordless home phone that came out in the early 80,s that had the telescopic antenna and would work nearly a half a mile down the road or more from your house>?

Well those phones were in the 46-49 mhz range and that is why they had such a good range on them as they were in a lower frequency.

Then the fcc said pretty much these phones talk to far away from the base so then they opened up the 2.4 ghz range for home cordless phones and then opened up the 5+ghz band for them and if you have noticed these new phones work fine unless you get outside your house or property and you will lose the call everytime

Now if you notice the state hiway patrol cars (state troopers) they have usually a long steel whip antenna on their cars among others, well this is because they cover the whole state and their radio systems are in the 42 mhz range and purposly so so that they can cover the whole state with their radios and many times can talk to another car 100,s of miles away direct w/out going thru a repeater tower.
As a matter of fact if you live on the east coast and have a police scanner w an outside antenna hooked to it then you can clearly hear the california hwy patrol all the way over on the west coast in the 42mhz band

Now of course you remember 911 and that when the towers fell that the nyfd lost communication, well that was because they were in the new freq range of 800mhz (which is a joke and many cops have been killed because of it) and when the towers went down there radios wouldnt talk accross the street, so thats why they swicthed all there radios back to the vhf high band 147-174mhz and in the uhf band of 440-512mhz.

Now many say well, my cell phone in analog is in the 900mhz range and in digital its in the 1900mhz range and i can talk from florida to california on the walkie talkie part of the phone, well this is a big missconception as you are really only hitting a local cell tower and then going thru the phone lines to the tower at the other end.

Now cb,rs use the upper 29mhz band and talk all over the world
and sw radio is way down below 1mhz into the khz band and they are heard all over the world.

So the point im trying to make is dont be fooled into thinking this new 2.4ghz band is so great as its a well known fact among us techs that the higher up you go in frequency the less range you have and most all the wireless cams that many attach to there rc projects are also in the 2.4ghz band and will cause major interference in the video from the 2.4ghz transmitter/reciever.
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Old 07-19-2007, 10:52 PM   #7
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tvtech,

I'm a little techno savvy....not as much as you - but doesnt power play into range? 200 mW vs 1 watt?

I've got the dx7, not so much for freq issues but it does keep peace of mind and the radio has many options for alot of us to grow into. I've researched the wireless camera option and went with .9 Ghz aka 900 Mhz which a good number of people have had success with the 2.4 Ghz radios.

You did present some interesting points on different frequencies, thanks

And thanks Ed for the writeup! Very informative-


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Old 07-19-2007, 10:58 PM   #8
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I also need and forgots to mention that 2.4 ghx is concidered a microwave frequency and is easily and very susspectible to many forms of interference that could totally kill communication between your transmitter and reciever in the plane, im talking just leaves on a tree, any type of metal buildings close by,even a cell phone tower will kill the signal and even your cell phone you have strapped on your belt clip can kill it especially if you use nextel as they are the most powerfull of all cell phones due to their lack of putting up more towers the cell phones see,s a weak signal most of the time and in doin so will transmit every few seconds its nam id and do so at full power killing communication tween your transmitter to the reciever as these phones are in the 1.9ghz range and close enough to the 2.4 ghz band to kill it.

Im not here posting doom and gloom but instead just letting you know to be careful as this is an expensive hobby and dont want to see anyone who has spent many hours and tons of money on there plane or heli and have it crash and be totaled due to radio probs.
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Old 07-19-2007, 11:07 PM   #9
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Originally Posted by aviatordave View Post
tvtech,

I'm a little techno savvy....not as much as you - but doesnt power play into range? 200 mW vs 1 watt?

I've got the dx7, not so much for freq issues but it does keep peace of mind and the radio has many options for alot of us to grow into. I've researched the wireless camera option and went with .9 Ghz which a good number of people have had succes with the 2.4 Ghz radios.

You did present some interesting points on different frequencies, thanks

And thanks Ed for the writeup! Very informative-
Yea power does play a part-
heres an example
a walkie talkie at 1 watt out in the 42mhz band will transmit several miles direct.
a walkie talkie in the 2.4 ghz range at 1 watt will transmit maybe 1/4 mile direct however 2.4ghz at 1 watt will literally burn you/cook you as posted above its microwave and your microwave oven operates and cooks just barley above it at 2.45ghz.



Wait .9GHz?
You mean 4.9ghz?
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Old 07-19-2007, 11:22 PM   #10
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Very good write up thanks!

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Old 07-19-2007, 11:35 PM   #11
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Originally Posted by tvtech3 View Post
Now if you notice the state hiway patrol cars (state troopers) they have usually a long steel whip antenna on their cars among others, well this is because they cover the whole state and their radio systems are in the 42 mhz range and purposly so so that they can cover the whole state with their radios and many times can talk to another car 100,s of miles away direct w/out going thru a repeater tower.
As a matter of fact if you live on the east coast and have a police scanner w an outside antenna hooked to it then you can clearly hear the california hwy patrol all the way over on the west coast in the 42mhz band

Now of course you remember 911 and that when the towers fell that the nyfd lost communication, well that was because they were in the new freq range of 800mhz (which is a joke and many cops have been killed because of it) and when the towers went down there radios wouldnt talk accross the street, so thats why they swicthed all there radios back to the vhf high band 147-174mhz and in the uhf band of 440-512mhz.
Well, I'm not sure what state YOU live in, but here in Illinois, the State troopers do not cover the entire state on their daily patrol. The state of Illinois is broken up into 21 districts, each district being on average 4-5 counties each. And, yes, most of the Illinois State Police cars have that long whip-antenna on their car, to use the 42MHz radio system they have utilized since the 1970's. As for talking to cars "100's of miles" away, that simply does not work. They can talk to their district headquarters from quite a distance, but 100 miles is usually not the case.

As it is, the FCC has told these State Police agencies using these 42MHz radio systems that they have to relocate to a different radio spectrum. Also, in the case of the Illinois State Police, it is becoming increasingly difficult to keep the radio systems working, both mobile and base, as the parts are harder and harder to find, and finding technicians knowledgeable in their repair is becoming rather difficult as well.

Hence, many agencies are switching to an 800 or 900MHz trunked radio system. The Illinois State Police are in the process of converting the entire fleet of ISP vehicles and base stations to Motorolla equipment, with the whole system named StarCOM21. This will eliminate the whip antenna. The contract between Motorolla and the State of Illinois requires a minimum coverage area of 95% of the state with mobile units. I have used this system; it is very much like NEXTEL, and the sound quality is incredible.

How do I know this? I am an 18 yr law enforcement telecommunications specialist, with 16 yrs on the Illinois State Police.

I just felt like I should step in; some of that info seemed a little far-fetched.

As for the radio problems on 9-11, well, not only did they lose communications when the Towers fell, but their radio system was so overtaxed by the overwhelming number of users attempting to talk on the system, failure was just about inevitable.

We may now go back to on-topic discussions. Sorry, Ed, if I hijacked your thread.

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Old 07-19-2007, 11:36 PM   #12
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Go Spektrum!

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Old 07-19-2007, 11:37 PM   #13
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Originally Posted by Tinman View Post
Go Spektrum!
Hey Brian, I just got a call from Spektrum saying you were cleared to be my wingman!

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Old 07-19-2007, 11:39 PM   #14
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Originally Posted by gfdengine204 View Post
Hey Brian, I just got a call from Spektrum saying you were cleared to be my wingman!
Haha your a funny man. So I HAVE to be your wingman cause I only have a DX6 and you have the DX7 ??

hehe

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Old 07-19-2007, 11:40 PM   #15
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Originally Posted by Tinman View Post
Haha your a funny man. So I HAVE to be your wingman cause I only have a DX6 and you have the DX7 ??

hehe
Pretty much, yeah. Sounds as good a reason as any. And, I'm older.

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Old 07-19-2007, 11:42 PM   #16
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Lol ok as u say.
Not here to argue, just when your officers are in a life and death call and they key their 800-900mhz motorolas and here the dreaded bzzz bzzz bonk bonk no contact w/repeater alert tones while there being shot at will bring a whole other story and wont be the first one.

So istead of keeping the officers safe with there older trusted radio systems they are putting their lives in danger w/these new short range radio frequencies and also having to continually clutter up peoples yards/interestions etc with towers to be able to pick up these extremly weak radio signals and rebroacast them.
I guarantee its these towers that are also playing a big part in the l.o.s of many hobbiest using the new 2.4ghz rc systems.
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Old 07-19-2007, 11:42 PM   #17
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Works for me, I'll be flying my P-51 with 2.4 ghz technology!

wooo hooooo great balls of fire!

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Old 07-20-2007, 03:30 AM   #18
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Originally Posted by tvtech3 View Post
Lol ok as u say.
Not here to argue, just when your officers are in a life and death call and they key their 800-900mhz motorolas and here the dreaded bzzz bzzz bonk bonk no contact w/repeater alert tones while there being shot at will bring a whole other story and wont be the first one.

So istead of keeping the officers safe with there older trusted radio systems they are putting their lives in danger w/these new short range radio frequencies and also having to continually clutter up peoples yards/interestions etc with towers to be able to pick up these extremly weak radio signals and rebroacast them.
I guarantee its these towers that are also playing a big part in the l.o.s of many hobbiest using the new 2.4ghz rc systems.

"Not to argue" yet that's what you do. When an officer is in a life/death situation, they are trained to deal with the situation, regardless if they can call for help or not. That's why they are issued weapons and taught survival skills. Besides... a 42MHz system can be busy too....like when another officer is using it. Then, when the second officer keys his mike, generally all you hear is garbled garbage. Now granted, for a trained ear, something acquired with training and time on-the-job, I may be able to pick out what the officer in trouble is saying, but sometimes that is simply impossible.

As for cluttering up peoples yards and intersections, Motorola has been using existing structure as much as possible for tower locations.

When you say you "guarantee" that these towers are playing a big part, how exactly do you plan to guarantee? After all, my club flying field is across the road from a cell tower, and (knock on wood) I have never had an issue with my Spektrum DX7.

Again, Ed and everyone else, I don't mean to hijack your thread, but this is exactly the kind of bunk that attempts to give Spread Spectrum (of ANY brand) a black eye. It's a new technology, and naysayers and doomsayers are going to whack it. It's has been proving itself AT LEAST as reliable as 72MHz, and in many ways very superior.

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Old 07-20-2007, 04:39 AM   #19
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Default Back on Topic...Telemetry

Several posters have cited the potential for telemetry, using 2-way comms, as an advantage of XPS.

But hasn't Spektrum also said they could do this? And unlike XPS, Spektrum already has some real products using telemetry for the RC car market, unlike XPS's vapourware.

I am not for or against any particular manufacturer - I just want to try to get the facts straight...


...and BTW, I also don't think that what tvtech says is totally correct. For example, if a cell phone generates so much interference it can knock out an RC TX, then how come half a dozen people can all sit in the same bus and all talk on their phones without interfering with each other? (I am an engineer who has worked on more than a dozen cellphone networks all over the world, if you feel that is relevant).
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Old 07-20-2007, 04:47 AM   #20
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Originally Posted by marchino61 View Post
Several posters have cited the potential for telemetry, using 2-way comms, as an advantage of XPS.

But hasn't Spektrum also said they could do this? And unlike XPS, Spektrum already has some real products using telemetry for the RC car market, unlike XPS's vapourware.

I am not for or against any particular manufacturer - I just want to try to get the facts straight...


...and BTW, I also don't think that what tvtech says is totally correct. For example, if a cell phone generates so much interference it can knock out an RC TX, then how come half a dozen people can all sit in the same bus and all talk on their phones without interfering with each other? (I am an engineer who has worked on more than a dozen cellphone networks all over the world, if you feel that is relevant).
Well ... from personal experience, I can say that the danger from cellphones is minimal.

Just last night, I was flying with my DX6, while talking on my cellphone through a bluetooth headset.

There was also a cell tower visible on a hill on the far shore of the lake I was flying on.

Now, if that isn't a recipe for cellphone generated interference, I don't know what one would be.

TVTech was talking about issues with range ... but the scale he was talking about is completely irrelevant for RC flight. I don't know about you, but I have trouble seeing my plane to control it from a few hundred YARDS away let alone a few tens (or hundreds) of miles that the longer wavelengths are capable of. Oh ... and by the way ... satellite signals are microwave too.

Finally, the spread spectrum technology is more than just straight analog signals being sent and received ... it's digital with error correction, and even the DX6 (AR6000) receivers have dual receivers built in to maintain a clear signal.

I hear lots more people complaining about glitching and getting shot down with the 72MHZ gear than I do from people with spread spectrum technology. So, it's all well and good to spout a bunch of theory, but when you get out to the flying field the proof is there in your hands.
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Old 07-20-2007, 05:29 AM   #21
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Originally Posted by marchino61 View Post
But hasn't Spektrum also said they could do this? And unlike XPS, Spektrum already has some real products using telemetry for the RC car market, unlike XPS's vapourware.
Could, haven't seen or heard anything from Spektrum that indicates they are going to do it tho, whereas XPS has said they are. We'll see what comes out.
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Old 07-20-2007, 05:31 AM   #22
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TVTech

CHP is indeed on 42Mhz...I know cuz I have them all programmed into my 796D...but they are FM, not AM. That's line of sight communication and that means repeaters. CHP's whip antenna is simply a function of the freq, not the range. -Rod-

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Old 07-20-2007, 06:05 AM   #23
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Originally Posted by bsoder View Post
Could, haven't seen or heard anything from Spektrum that indicates they are going to do it tho, whereas XPS has said they are. We'll see what comes out.
As someone who has worked for more than 20 years in technology-related businesses, I tend to tune out what companies promise to deliver and focus only on what is really out there in the market. Especially when dealing with a company whose track record only extends back months, rather than years.
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Old 07-20-2007, 06:41 AM   #24
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Originally Posted by marchino61 View Post
As someone who has worked for more than 20 years in technology-related businesses, I tend to tune out what companies promise to deliver and focus only on what is really out there in the market. Especially when dealing with a company whose track record only extends back months, rather than years.
I can accept that - one thing to keep in mind tho, is that the XPS system already does 2-way, the receiver provides positive feedback to the tx that it's receiving the signal.
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Old 07-20-2007, 07:12 AM   #25
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I fly with a DX-6 and a DX-7 100 yards form a cell phone tower with my cell phone on my hip. Never a problem.

Perhaps, tvtech, you should read the 2.4 Ghz guidelines from the FCC regarding interference between users on the frequency and then study how Spektrum and Futaba guarantee that their transmitters and receivers will talk to each other and only to each other.

There are so many discrepancies in your statements, such as saying that 1.9 Ghz will kill signals on 2.4 Ghz equipment. If that were so, you could not talk on your cordless phone while your cell phone was turned on.

And I don't think I will be using my 2.4 Ghz DX-7 to heat my water for hot chocolate.

I don't know why you are making all these statements in sweeping generalities about failures of the transmitters without justification. "They said" is not justification.

Apparently you are here posting doom and gloom since you joined the forum just to do so.

Just my humble opinion.

Again, as others have said Ed, sorry for going off on a tangent.

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