Artifact Details


Whirlwind vacuum tube module PPG BA

Catalog Number



Physical object


This plug-in module is formed by an open chassis on three sides and a Bakelite plug with 24 flat contacts on the fourth side. A handle is attached on the end of the chassis opposite the connector. A flange on each side holds a captive screw used for securing the module into one of the positions of the ten-module rack.

Two vacuum tube sockets are mounted on the same end as the handle. Six rows of phenolic solder terminal strips span the space between the two sides of the chassis to which passive components are soldered. Point-to-point wiring connects the connector, the tube socket pins, and the solder terminal strips.

The tube complement is one 2D21 and one 6145.

A red tag is attached to the handle by a string; typed on the tag is "THIS UNIT IS NOT TO BE USED TO REPLACE A STANDARD UNIT. THIS UNIT MODIFIED) Mod No. 5754

Identifying Numbers

Serial number 4 Stamped in white ink between the vacuum tubes.


overall: 1 5/8 in x 5 1/4 in x 9 1/4 in


Component/vacuum tube

Lot Number