United States. Air Force. Cambridge Research Laboratories
Written in grease pencil on trace side
overall: 1/2 in x 4 1/2 in x 6 in
Pentode and Gate module consists of a circuit board with three miniature vacuum tubes on the component side in a three sided orange frame. Handwritten text in upper right corner reads "OK". There is a piece of masking tape on the back obscuring the handwritten text.