have a 60's-70's f8t5 ge that is fussy starting in a electronic preheat 12v fixture and a manual preheat ac desklamp.
noticed some other vintage tubes doing this.
dim,pink like neon fill gas.warm up ok.
i remember the gas mix slowly leaking from laser tubes and since these are older and seem to have neon as fill maybe they are slowly leaking?
other old tubes seem ok.i thought argon was used?
the glow is definately neon.reddish orange flashing on electronic i.s. in the ends vs violet.

Lately there have Ben quite a few complaints here about  G-E fluorescent bulbs going to air ,

No wonder so many people started Switching over to westinghouse fluorescent bulbs ,

Think about it , how many westinghouse blackenders have you heard of that have lost there vacuum  prematurely  ?  I certainly haven't heard of any ,


uote author=toomanybulbs link=topic=3674.msg23514#msg23514 date=1409517339]
have a 60's-70's f8t5 ge that is fussy starting in a electronic preheat 12v fixture and a manual preheat ac desklamp.
noticed some other vintage tubes doing this.
dim,pink like neon fill gas.warm up ok.
i remember the gas mix slowly leaking from laser tubes and since these are older and seem to have neon as fill maybe they are slowly leaking?
other old tubes seem ok.i thought argon was used?
the glow is definately neon.reddish orange flashing on electronic i.s. in the ends vs violet.
[/quote]

I don't think the miniature T5's (not the modern HO) ever used Neon, I would guess there was just argon.

My experience with old tubes, sitting long time in some shelf is, they start very dim and pinkish, only after some hour they settle to rather normal glow.

The pink glow may as well originate from just missing mercury: The discharge then burns just in the argon fill, which radiates only in UV. This then excites the phosphor. As the wavelenghts are different, the phosphor radiates with different spectrum as well.

But it could be a contamination as well, the few hour burning then cleans that out...