Manufacturer: JAMES MILLEN Manufacturing Co., Inc. (USA)
Model: 90902, S#608
Purpose: Monitor Oscilloscope
This is a 19in rack mounted unit. The 90902 was built over a long period by Millen. Earlier units like this one have the power supply with individual components. Later versions are 90902-2 have a power supply module 90202.
Scopes like this were mainly used for frequency matching and alignment. It could conveniently be mounted in a 19in rack together with other equipment. Vertical and horizontal inputs are at the front and also the rear.
A simple, robust scope which enjoyed a lot of popularity.