[Amps] a 'circuits' question

[Dan Sawyer]

This is a circuits question from a 575 curve tracer being used to match 
MOSFETs for an HF amp so it is a least close to topic. The problem is 
the difference in granularity between the 'steps' circuit and the 'zero' 
adjust circuit. The bias of the power MOSFETs is high enough so that 
only higher numbered steps get displayed the granularity per step is too 
high. The result is only 2 steps per trace get displayed.

The circuit that produces this is a voltage adder with the steps input 
coming through a 90K Ohm resister and the bias coming through a 600K 
ohm. My question is can I substitute a smaller resister for the bias? I 
was thinking of 150K ohm. This would effectively increase the bias to 
the point where it was turning on the MOSFET and the steps drive could 
be reduced to a low enough value where multiple steps were observed.

Is this a feasible modification??

Thanks,
Dan