AS3X Gain Adjust via L/R trim DX9

[Hugh Wiedman]

Someone may have touched on this earlier, but couldn't find it. Upgraded my DX6 to the DX9 a couple of months ago and could not find out what the L & R trim switches on the DX9 were for, except in an obscure post in a forum saying something about it being used by Helicopter guys. When I transferred over all my models to the DX9, the only thing that didn't "work" correctly was in the models that I had programmed my AR636 for "relative" gains versus the default "absolute", it wasn't working correctly, everything was at 100% gains programmed into the receiver, even though I had set some up in my DX6 for less than 100% or even 0% (gains off). When you set gains to relative, it allows you to increase/decrease gains in flight from your transmitter, while if set to absolute, the gains are exactly as you program them only. With the DX6, that is done using the roller. I now find out that you can use either the left or right trim switch to do that with the DX9 (and presumably any other transmitter that has those switches) and not the roller. This is a great tool that allows you to decrease the gains if necessary in flight (if for example you get oscillation) or increase gains without having to land, reprogram the receiver and try again. Presumably, this is how HH sets gains on BNF planes that come with an AS3X receiver. Since you can set 3 flight modes in the receiver and change between them using a switch on the transmitter, I suspect they start out with 100% gains on a different surface in each of the 3 FM's. Then take it up and check the oscillation in each individual surface and reduce/increase the gain accordingly. Then land and you can combine all three "maximum" gains on each surface in each FM. Very COOL! The trim switches are much easier to use in flight than the roller.