AD01-D 10 Bit A/D Converter Engineering Change Order Log

This document is an Engineering Change Order Log for the AD01-D 10 Bit A/D Converter, detailing a series of engineering and field change orders (ECOs/FCOs) issued from October 1970 to December 1973. The log identifies specific problems encountered with the AD01-D unit and its documentation, along with the corresponding corrections and their impact on Master Drawing List (ML) revisions, in-plant effectivity, and field retrofits.

Key issues addressed include:

• Documentation errors: Incorrect part numbers, labels, drawing errors, and updates to specifications, calibration, and accessory lists.
• Manufacturing and cost reduction: Changes to simplify manufacturing processes and reduce costs.
• Performance and hardware fixes: Addressing issues like AH05 Sign Option instability, multiplexer expansion, poor differential linearity (skipping states) with the A812 converter, lack of AC/DCLO indication, and compatibility problems with other modules.
• Calibration procedures: Enhancing and correcting calibration procedures, especially for use with different PDP-11 models.
• Wiring and assembly: Corrections to wire lists and assembly panel numbering.

Many entries note field effectivity, indicating whether existing units require retrofit at customer expense or as part of scheduled maintenance. Each change typically results in a new revision of the AD01 Master Drawing List.