7jp4 tube is it bad?

[fumplet]

Hooked up my new 7vt5r tube to my known working ts-18 chassis and it worked for a while but did I just bump the vertical height knob or can these tubes short out and start to load down the vertical circuit causeing the height to shrink bottom to top. Image was centered top to bottom but shrunk. I switched it off and hooked up the original good tube to my good chassis and it showed normal raster. I do have the sencore cr 70 tester but as Ive read chassis hookup is best for tests?