On Sat, 15 Mar 2014 10:56:47 -0000, Dave Plowman (News) wrote:

In article ,
Andrew Mawson wrote:
Never had this before. Fluorescent tubes in my experience either work at
full brightness, flicker, or just the heaters glow.

I had a flickering tube, installed a new one, and it started fine but
was noticeably dimmer in the middle than at the ends. When I got it out
of the store, one pin had been bent, which I bent straight and I tested
the heater at that end with a meter - it was ok. Now obviously it's had
a clunk to bend the pin. If it had spoilt the seal and made a 'soft'
tube I'd expect the heaters to glow brightly then burn out which it
didn't. So what process makes for a dim tube? End 25% at both ends is
normal brightness. Could the phosphor have been dislodged in the middle
but not the ends?

I'll leave it in place and observe it's progress as where it is is over a
shelf anyway.

I recently fitted one new tube in a twin fitting - smaller diameter than
the original - and it is slower to start and takes a short while to come
up to full. It's better than it was at first, though.

I've stopped using fluorescent tubes, they're very inefficient. As the tubes died, I replaced the fittings to take LEDs.

--
Saying that she is promiscuous is an understatement.
She'll go zero to sixty-nine in under fifteen seconds."