Use the throttle to elevmix on your throttle channel. You will have to have the feature turned on first under the options screen. I use it to keep one of my planes from climbing too muchat full throttle because the incidence is off. But it is easier to use the elv to keep the tail on the ground. Just don't jamb on the gas at take off. On my warbirds I hold full elev to start, then ease off as Igain speed until the tail starts to lift off. I would also check your CG and your thrust angles on the engine. You really should resolve the issue mechanically first before resorting to radio mixing