ORIGINAL: Ryan Smith
I'm not sure what horror stories people are spreading around, DSM is bulletproof.
FASST isn't even real FHSS, so I don't know what the big advantage of it would be. You're still limited to a small handful of frequencies.
Ryan,
I'm curious as to how FASST isn't real FHSS? The radio changes frequencies every 2 milliseconds. Yes, there are a finite number of frequencies, however by changing constantly you help reduce the possibility of failures. There is NO truely perfect system out there as it is impossible anytime you are using RF. Just ask the companies that spend billions on it for the defense industry, it is still never perfect, however by hopping you are MUCH less likely to encounter issues. An example of an issue that could happen is this. You have multiple flight lines that are separated by quite a ways. Fairly easily you could have a TX/RX at one site pick up 2 channels on the ground and a different TX/RX combo at another site pick up the same two channels. While the planes are on the ground or in front of you there likely would be no issue, but as the planes got close for example if both were at the end of their flight line making a turn, conceivably there could be issues as the planes got closer to each other. I am actually sitting next to a guy who does RF testing for a living. I let him read the descriptions of both systems and described the exact scenario I just mentioned to you and was told "ABSOLUTELY that could happen if you have a large number of people turned on at the same time." When you are stuck on a channel/channels and something interferes with it, there is nothing your system can do, but if you system can change or changes automatically to another channel you have a much better chance of saving the plane. I don't know that this is a major issue as small events with limited pilots, but at larger events it very could turn into a SERIOUS issue and apparently already has. Once again, NO system is perfect, but there are ways to make things better. I think the biggest reason DSM-J isn't being offered in the US is that the most pilots wouldn't want to sell all of their DSM stuff and start over.
People have had radio problems for years and always will. The technology is SIGNIFICANTLY better now than it was years ago, however the possibilities exist. I think the biggest problems now are user setup and lack of effort for proper setup on the rest of the equipment (ie batteries/servos/mechanical advantage). I make sure that ANYTHING I fly with failsafe capability has it setup. This way I could at least tell if the problem were a radio problem or lack of power to the system.
I personally prefer a module based system. Granted my antenna sticks out the back of the module, HOWEVER, 2 years down the road, if something newer comes out, I can buy the module setup instead of buying a new 14MZ to change to the new system.
Arch