BA11-K Mounting Box Manual

This document is a technical manual for the Digital Equipment Corporation (DEC) BA11-K Mounting Box, a 10.5-inch rack-mounted expander chassis designed for PDP-11 family computers (including the similar PDP-11/05S and 11/35S power systems).

The manual provides comprehensive information across five main areas:

1. Characteristics and Specifications: Details the physical dimensions, environmental characteristics, and electrical specifications (input/output power, voltage, current, ripple) of the BA11-K and its integrated H765 Power System. It notes variations for 115 Vac (BA11-KE) and 230 Vac (BA11-KF) input.
2. System Units, Options, and Harnesses: Describes how various system units (dedicated, general-purpose, blank) can be configured within the BA11-K, including Unibus connections and power distribution wire color coding. It emphasizes selecting options compatible with the power supply's capabilities.
3. H765 Power System: Offers a detailed mechanical and functional description of the power system, including its main components: multiple voltage regulators (H744, H745, H754, 5409730-YA), transformer assembly, AC input box, fans, and the power distribution board. It explains the theory of operation for the AC input, transformer, and regulator circuits (including voltage regulation, overcurrent, and overvoltage protection).
4. Maintenance: Outlines both preventive and corrective maintenance procedures. This includes required equipment, fault isolation steps, voltage regulator checks and adjustments, troubleshooting guides, and detailed instructions for the removal and replacement of all H765 power system subassemblies.
5. Unpacking and Installation: Provides guidance on unpacking the BA11-K, installing it into a cabinet, connecting the appropriate AC power (115V or 230V), and configuring remote power control. It also recommends post-installation system diagnostics.

The manual is intended for users performing installation, operation, and maintenance on the BA11-K and related PDP-11 power systems.