Okay guys, problem solved. Since this is my first helicopter, I can plead ignorance. I followed the procedure outlined in the above link, and now have a very good collective, with symmetrical power in both positive and negative stick. What I was neglecting was the three arms from the servos. They were out of adjustment giving me much too much positive pitch. I was thinking the only adjustment I had to deal with was the same ones used for tracking the blades. Now I know just enough to be dangerous. Should fly much better with a higher rotor speed. Thanks to all who posted.