[R-390] Series 500 IF Module

[Byron Tatum]

Hello-    I am considering converting an R-390 IF module to fit into an R-390A mainframe. I have some info on this but have seen posts that a schematic for the actual Servo Corporation Series 500 IF module exists. I have searched for one to no avail.     I was hoping to find this schematic to compare it to the R-390 IF module and aid in the conversion.     Also, I would like to add any R-725 technical info that is available to my files here in order to study.     Will pay any costs incurred if copying is required.Thanks all,Byron W5FH