???I had noticed one of the ACE / GE lamps at the radio station had a large black spot and it was growing. As I got ready to leave, I noticed the whole end had gotten jet black and was glowing purple on the end. Then I turned it off and on, and it came on bright orange on that end. The second time I did that it came on orange, rectified and shimmered and went to the dim glow that a 2 lamp rapid start fixture will do with an EOL lamp. I am replacing it with an older Mainlighter ( I have 6 new ones) and bringing the dead one home to polish off on a solid state lamp destroying ballast....

It burned steadily on the ballast made for the lamp. It pulsed a few times and it glowed faintly purple, then some faint  red.....then I noticed it was getting dim and all of a sudden SSSSSSSSSSSSSSSS!  What a BORING EOL on this lamp. It had melted one cathode lead halfway down and the glass stem was disformed. I guess that is what caused sudden failure.

All I can say is AWWWWW !!!!     

That's your typical cheap GE tube re-branded for ACE.  I've only had one or two used for shop lights that went past 5000 hours.  But this was years ago.  I'm sure things have changed since then, but most of the tubes I get now a days are Sylvania (awesome prices and a great rep from Sylvania) and a few Philips boxes that are left overs from a huge freight shipment that was all messed up.  I still have some of the early generation GE Ecolux F32T8s which I am running through the high use areas of my buildings, just merely so that I can use them up, they only last about 8000 hours on average before very dim starts with about 5 min run up time to full intensity.  Both ends seem to black up quickly.  Will get some photos. 

These older ACE / GE tubes have lasted forever. On at 6 AM off at 6 PM sometimes later. They have been in there 4 years or more. And there's no age marks on any of them except the one where the ballast was replaced, and it's got brown markings.  It's interesting that they get slightly dimmer .....aging phosphors..... and when the black spot starts it's a countdown to EOL.  It's also weird the older lamps start faster ....some instant starting when they become very aged.

Powell