Hello everyone! My first post on EEVBlog!
I got my hands on an old HP 3403A RMS Voltmeter. Amazing little instrument design.
She powers up on the bench fine. The 70's LED displays all work and controls seemed responsive.
Trouble came in on the actual input test. The AC function doesn't read. DC input no issues.
On tear down, I believe I located the culprit. It has what HP called at the time TCIa/b THERMOPILE (HPPart#0853-0014). It is a custom component from HP. I can't find any data on this can.
If anyone has a datasheet or even a description for that matter, it would be much appreciated.
Here are a few links to photos of the piece and associated circuitry.
https://postimg.cc/gallery/32dc5pNThanks!
Mitch