[Central-Electronics] 20A stumped

[Paul Kraemer]

While trying to align a 20A I find it impossible to get the first step 
correct balancing the red and green coil signals at the wipers of the two 
null pots.
Best I can get adjusting the spacing and tuning the slugs is 5v rms on pot A 
and 2.5v rms on pot B

Other than that the signals really look good on a scope running into a dummy 
load.  Aside from the other issue that full output  is only about 10w which 
I will address after the first issue is resolved

What am I missing?

Thanks
Paul K0UYA