Kirk I have some of these in my L1011. I was running a 5.1volt duralite regulator and later learned that the 2.4 system would be better off at 6 volt. So I removed the regulator and the 2721's went crazy after a fresh charge on the batts. The fix was a inline regulator a friend had. I just put it in line between the rx and the servo. The regulator is a simple looking 6"extension and I haven't found a source for these yet. I think JR use to sell them. I will check with Andy @electric dynamics also. These are very good servos at 4.8v. Scott