ORIGINAL: idedave
I have both a Futaba Fasst system and a Spektrum DX7. The Fasst system, which I have had the longest, has performed flawlessly and exactly as expected. The DX7 has shown the 'drop out' glitch often referred to in the forums. Read all the forums very carefully and compare the number of 'loss of control' posts.
The reasons that I purchased the DX7 were the availability of low cost receivers, model identifier and a 20 model memory but now I do not trust it and this screws up the fun of flying. I am going to relegate the DX7 to flying foamies and park flyers where I do not have the money or sweat equity at risk.
I also find the two receiver approach to be a pain during installation and I now suspect that this is a band aid to fix a fundamental design weakness.
My research has led me to believe that the Spektrum design is not as fundamentally robust as the Futaba. They are not equivalent and use entirely different approaches to spread spectrum technology.
Many on these forums will vehemently defend the Spektrum approach but this is to be expected as nobody, including me, likes to face having made a poor decision. The data was available on the forums and I did not do enough research.
Of our club of 73, at least 3 of us have had drop out problems with the DX7 and this is at least 30% of those using the system.
Batteries are definitely an issue. Spektrum says use a 5 cell battery but do not supply this pack with the system and it should not be required. The reason that batteries are such an issue is that the Spektrum approach to implementing spread spectrum is extremely vulnerable to noise on the power/ground lines supplying the receiver. A noise spike on the power supply sends the receiver into a reboot mode which can take up to 13 seconds to complete. No amount of software fixes are going to get around this as it is inherent in the approach they use to implementing the system. Whenever motors are on the same power supply bus, as is always the case because we are driving servos, there will be noise spikes on the ground and power lines. I think that it is mostly the luck of the draw if you happen to get a noisy servo. Capacitor filtering will probably help as will a higher voltage supply pack and low internal battery impedance but these are not fixes rather they just lower the probability of experiencing the problem.
Hope this helps you make an informed decision.
There is a lot of incorrect or dated information in this post that I would not use to help make up my mind. The reboot issue was fixed quite some time ago and if you happen to have an older receiver then Spektrum will upgrade it for free. It was caused by the receiver battery voltage dropping below a certain value. The battery information in the post is very misleading in that the new 2.4 ghz receivers of all manufacturers have a low voltage threshold that did not cause a problem with the 72 mhz systems and using a 5 cell battery is simply a good, cheap solution to help prevent the problem - remember all manufacturers systems have this same issue for the 2.4 ghz systems. Next time you are at the field see how many experienced 2.4 flyers are still using 4 cell batteries except for parkfliers.
Do yourself a favor and also look at the Airtronics 2.4 ghz system. They are an excellent company that many of us have dealt with for years. You get two receivers and a transmitter for $229.
I do not own a Futaba, Spektrum or Airtronics 2.4 system so I don't think I am being biased. You have some great choices so take your time and get the big picture.
Howard