R603

This document is a schematic diagram for the PULSE AMPLIFIER R603, a circuit designed by Digital Equipment Corporation in 1964 (Revision 6).

The circuit features six cascaded stages (Q1 through Q6), each built around a DEC 2894-2B transistor. Each stage incorporates a network of resistors, diodes (primarily D-662 type), and capacitors (e.g., 100 MMFD, 330 MMFD, 0.01 MFD, 0.1 MFD).

The amplifier operates with a positive supply line labeled "OA+10V(A) OC,H,N,U GND" and a negative supply line labeled "OB-15V".

General notes indicate that resistors are 1/4W with a 10% tolerance (though some are specifically marked 5%), diodes are generally D-664 (while D-662 are prevalent in the diagram), and capacitors are specified in MMFD (micromicrofarads/picofarads) unless otherwise noted. Transistors are generally DEC 3639-C (while specific components are DEC 2894-2B).