aeajr
Posts: 5460
Joined: 1/14/2003
From: Long Island,
NY, USA
Status: offline
|
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, Extreme Power Systems 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 - Extreme Power Systems
www.extremepowersystems.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
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.
< Message edited by aeajr -- 7/19/2007 5:55:53 PM >
_____________________________
Clear Skies and Safe Flying!
Ed Anderson
Moderator
Park Pilot Program Partner
|
Printable Version
All Forums >> Radios, Batteries, Clubhouse and more >> RC Radios, Transmitters, Receivers, Servos, gyros >> 2.4 GHz - A Broad Market Review 
2.4 GHz - A Broad Market Review - 
