I hope this is clear enough without being too techo.
FASST is a spread spectrum system which means it transmits on multiple frequencies at the same time within a "band" of frequencies. The receiver then picks the best (not necessarily the strongest) signal frequency and uses it. Being spread spectrum the "switch" between each discrete frequency happens very quickly. The transmitter doesn't know what, if any, interference there is and just transmits on all frequencies in the spread spectrum.
FASST receivers have two antennas on one receiver (not two receivers as I have seen incorrectly stated) and the receiver is comparing all if the signals on each part of the spread spectrum. Interference will reduce the quality of the signal and thus it will be ignored in favour of a better signal.
FASST is thus a very robust transmission protocol that is quite tolerant to "noisy" radio environments.
FHSS is a frequency hopping protocol. This means that the transmitter will "jump" from frequency to frequency as a way to mitigate any possible interference (again the transmitter doesn't know what, if any, interference there is). The transmitter only ever transmits on one frequency at a time, however the jumping happens very fast.
The FHSS receiver will "listen" on all possible frequencies and read the received signal if it's of sufficient quality to be meaningful. If there isn't a good enough signal then nothing happens.



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So if we were to rate them in terms of quality, would frequency hoping be preferred to taking the strongest signal? I only ask because i have NEVER had an issue with my futaba receivers dropping out.

 

Both types of Futaba receivers are good. FASST is inherently better simply because it transmits on multiple frequencies at once (i.e. spread across the spectrum) whereas FHSS transmits on only one at a time.
As an example the same technology used in FASST is used for industrial radio in factories and processing plants.


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I think that says it all really. It must be very reliable if it is used in those applications.

 

Rumor has it that futaba had a 2.4ghz system before spektrum but did not want to release it as it had known issues... it released its own when they felt they had a reliable system... apparently the original non released system was very much like spektrum first released version which people seem to find issues with...

Just what I heard from a while ago..

Citizen#024

 

The range that FASST gets still amazes me. Watch a glider pilot to see what I mean, you can barely see some of those big gliders & it all still works.


Citizen #186

 

There's not much wrong with the Spektrum gear that can't be put down to poor installation. The basic protocol is sound and works well.
Even a Futaba setup can be cocked up by poor installation. I've seen some shockers.


Citizen #186