[Test-Equipment] HP-334A

[Miles B. Anderson, K2CBY]

The first question is whether the analyzer won't auto-null or whether it
won't null in straight manual.

I had a case where the manual null was passable but the auto-null seemed to
un-null the dip. It turned out to be shorted tantalum caps (note the
plural -- seems to me more than one had gone south) in the auto-null control
board.

I would not dig into the lamp-photocell assemblies unless I had exhausted
most or all the other possibilities. I strongly suspect that the photocells
are not obtainable as replacement parts if you damage one.

Miles Anderson, K2CBY