The Tektronix 202 is an oscilloscope cart for 500-series scopes.
The standard 202 has a tray that is 14" wide. There is a special version 202-1 mod 52, which is 14.75" wide to accommodate the larger 519 scope.
Ex-Tek engineer John Addis recalls his purchase of a Tek 202 cart:
I purchased my 202 Model A Scopemobile back when I was in college in 1963 and had just purchased a used 545A (then still in production) for $800 (half price). The 545A was a great investment since it probably contributed in several ways to my getting a job at Tektronix.
I put the scope on the Scopemobile and had it in my dorm room. At the time there were probably few lab scopes at the Institute that were better than my 545A with Type L plugin. That would be a difficult achievement nowadays.
One thing I noticed is that the 545A could slide around on the Scopemobile, especially when tilted forward (down in front). So I drilled two holes in the Scopemobile table and drilled two holes in the bottom rail of the 545A. Alignment was crucial, of course, and I was careful enough that I got it right the first time. I tapped the holes in the 545A and ran two ¾” 10-32 screws through the Scopemobile table and into the 545A.
The 545A never budged a millimeter after that! The Scopemobile still holds the 545A and is in absolutely pristine condition. Thanks, Gale.