Henry Kolesnik wrote:
I got a couple of the subject tubes which are supposed to be "glow
modulator tubes". Best I can determine is that the light output will
vary with current but I can't find data sheet googling. If anyone has
pinout and/or data I'd sure like to see it. I think it might be a mid
1960s item as my 1957 Sylvania manual doesn't show it.
thanks

I have a Sylania Technical Manual of tube data sheets dated 1959 and
have the blue add-ons to 1960, and that tube is not listed anywhere in it.
Sorry.