ORIGINAL: bonebreak
The bad thing about having it on the throttle is that you have to be at half throttle, or better for it to count down(up). Once you go lower than half throttle, the timer stops until you throttle up past half again. I think it would have been better to have it at 1/4 throttle instead.
Actually you can set it at any throttle setting you want. I forget the exact steps, but you set the throttle stick where you want it, then set it by pressing a button or something like that. I have that radio and set my throttle for 3 clicks above the bottom. That lets me start the plane and keep the idle high until I start flying without running the timer.