Pete,

The digital informaiton on servo position is encoded by the TX in a pulse train, which takes a finite amount of time to transmit. As the radio operates, the pulse train gets sent over + over again to encode the positions of the sticks, dials +switches on the transmitter. The RX decodes, and puts out servo signals. The update rate is slower on 72 MHz systems than 2.4 Ghz systems. That's why the 2.4 systems feel more responsive. Fut and JR are having a marketing war over it now .. JR came out with the "SE" version of their radios, which were slightly faster than the stock Futaba 2.4 system .. and they are crowing about "Faster than Fast" (meaning Faster than FASST) .. they are 11 ms frame rate. Then Futaba came out with a series of faster RXs that are 7 ms update. Let the fun begin. Good luck if you can tell the difference .. Idon't think Iam that good :-)

Anyway, two channels, mixed to one another, should move together . if set up properly . .and will do so if the stick is moved slowly. But if the stick is moved very fast the delay between the update on one channel and another is actually visible. On the newer Futaba radios (don't know about JR, someone can chime in...), channels are grouped into small blocks of channels .. and within a block they update simultaneously, so that the delays occur between blocks, but within a block (of several channels) they all update together. It is good practice to put "related"channels together in groups, like ailerons, flaps, elevators, dual rudders, etc. All documented nicely in the manual.

As Bob says, one of the joys of a many-channel radio is not needing matchboxes, and wiring all servos direct. Makes setups very fast and easy. The grouping was created to get around the delay that is intrinsic with the idea of encoding the channel positions in a pulse train.

If this is NOTwhat was the observed "problem" with your plane then Iagree w/Bob .. find out what was up .. these gremlins, when ignored, ALWAYScome back to bite... if this was the problem, handle it with grouping. In all honesty, Idon't think it was ever much of a real issue, since we would not tend to make super-fast stick movements .. and in any case after a few milliseconds, the channels would be back to agreement. But it was still creepy to see the elevator halves move in slightly mismatched motion...

Dave