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General => General Discussion => Topic started by: Bean on March 08, 2022, 09:01:32 PM

Title: Causes of early vacuum loss
Post by: Bean on March 08, 2022, 09:01:32 PM

So I recently had a Philips Alto f40t12/d, one end wasn't lookin so good since I left it on and didn't notice it running cold cathode. The filament was still intact though, when I accidentally installed it with 3 pins connected on my electronic ballast the bad end glow orange for about 3 seconds then the lamp dimmed out. For a bit I think it still glowed a very dim color next to a plasma ball but it doesn't do anything now. I've peered inside the bulb, the entire bad filament is still there. Any ideas what caused vacuum loss on this lamp?

Title: Re: Causes of early vacuum loss
Post by: Medved on March 09, 2022, 12:18:31 AM

Poor adhesion of the glass to the lead in wires, crack in the glass that just propagated through the whole material,...

Title: Re: Causes of early vacuum loss
Post by: Bean on March 09, 2022, 06:52:10 AM

Makes sense, pretty unfortunate, I guess I'll be getting some new ones soon.

Title: Re: Causes of early vacuum loss
Post by: waterbug on March 11, 2022, 10:19:25 PM

Also overdriving the lamp with the wrong ballast, like connecting the 36W fluro to a 55W SOX ballast or 58W fluro ballast, after like one hour the lamp extinguishes and you can hear the "hiss" :lol:

Title: Re: Causes of early vacuum loss
Post by: Bean on March 12, 2022, 07:30:19 AM

I've heard two eol tubes hiss, both of em startled me. The f20 was super loud, I knew the f30 was coming because there wa s alittle hiss at first.