Tektronix 465

[heathkitman]

Hello,  I have a question about my Tektronix 465 oscilloscope. I hope this is the right place to post it. I’ve always loved the 465 and every hobbyist lab should have at least one analog scope. Mine works quite well except for the beam finder. When I press the beam finder button about ½ of the way down, there is a brief flash of a bold, horizontal line about 2 inches long and 3/16 high that then disappears completely. Looked at the schematic and it seems to be a rather simple circuit.  Could it be as simply as a failure of switch S400?  My other question is rather stupid. Most of the 465s that I’ve seen have a blue screen and a light blue trace, almost white. Mine has a decidedly green trace. I assume this is a function of the CRT that my unit has. Any thoughts?
Thank you.

[David Hess]

Could it be as simply as a failure of switch S400?

Yes, that is a common fault.  Cleaning and lubricating the switch will likely fix it.

Most of the 465s that I’ve seen have a blue screen and a light blue trace, almost white. Mine has a decidedly green trace. I assume this is a function of the CRT that my unit has. Any thoughts?

I have a couple of other Tektronix oscilloscopes with the same differences.  Despite having the same nominal CRTs or phosphors, some have a decidedly greener trace and some are bluer and whiter.  My guess is that there was some variation in the processing and application of the common P31 phosphor.