An interesting and long running thread.
Like many, I have a bit of a soft spot for the old HP435 meters and would like to have one working on the bench.
Since broken detectors do show up now and again at a decent price, has anyone successfully reworked one with busted thermocouples and modified for a diode front end? I know it’s small and very fiddly, but is that not easier than trying to build one from scratch?
EI2KU