Problem with calibration of Clarke Hess 828

Hi,

i,ve a problem with calibrator Clarke Hess 828.

My 828 has much error on 100 volt and 1k volt range DC generation.
I've calibrated the unit with the user manul of 828 in range 10 volt
as descibed.
In range 1volt and 10 volt thetension generatd is perfect,in 100 Volt
an 1Kv i've an error more of 5%.
What can be?
Sombebody has already resolved this problem
Thanks

Ciao,
MAX

 

Sorry can't help but how did you get a manual?. Looked high and low for
one, no joy.
My own unit is working fine but need to replace one of the thumbwheels.
john