In article , Susan P writes:
I am in the UK.

I have an old 13 watt linear fluorescent lamp (20 inch long) which is
not really bright enough for my needs.

Can I replace the tube with a tube of a different technology so it is
brighter?


If the lamp is really old, then a new replacement lamp (bulb)
may help. Fluorescent lamps lose some light output with time,
and if the lamp is very old (or was really cheap) a new lamp
may be more efficient and give you more light.

And, not to be insulting, but the next most common cause of
loss of light output is dirt. You don't say if the fixture is
open or closed, or if there is any cover over the lamp, but
dirt can cause more light loss than you might think.

If those two things don't do enough, then you'll probably need
to get a different fixture. Re-wiring an existing unit to take
a different lamp can be done, but it's really for people with
experience, or who like to tinker and don't mind if they spend
more to make the change than to buy a new lamp.