width problem

[radio nut]

First question, I do not know. The paper that came with it said exact replacement. This fly is two seperate coils with a metal U that goes inside of each coil. As you adjust the width it will move out or in one coil while pivoting inside the other. Yes it moves smoothly and as much as the original. Using a variac to make the line voltage 117 like the diagram inorder to check voltages, its 235 volt line is 236. this goes to the damper and then to the fly but the 435 boost line is only 410.that goes to the horiz. output tube grid and it is giving the tube only 127, not 135. If I boost my B+ the width stays the same even if boost voltage goes up.