[sdiy] LM311 woes

[Ian Fritz]

Does anyone have experience with performance of LM311N's from different 
manufacturers?

I got a VCO working using some National units out of my stash.  (No idea 
how old, but old.) Then I subbed new devices from ON and the oscillator 
wouldn't even run!  I finally got it working, but only under much more 
restricted conditions than the original.

Any ideas as to why would be welcome.  I didn't see any obvious differences 
in the data sheets.

Ian