[R-390] AGC Varies ?

[Gordon]

I have a quick question that I hope someone can help me with.
   With 100MV into the antenna matched port, shouldn't I get the same 
reading on the carrier meter regardless of which position the AGC switch 
is in?
Mine varies from Fast-Med-Slow. In fact Fast will show full scale but 
slow only goes to 20 or so with the same input signal strength.
I am still searching for an EAC IF Module.

Thanks,
Gordon
N6WK