I suspect the problem with Tungsten might be oxidation. H P
I would think that once proper vacuum has been reached there
won't be enough o2 left to cause any appreciable wear.
True enough; I think it's quite likely that the degree of vacuum attained by
H P Friedrichs wasn't too high.
Friedrichs has used tungsten light bulb filaments in homemade triodes
etc. See his book Instruments of Amplification
Ohho sounds like I'll have to buy this book!
I can confirm it's a great read!
Hans
