DIYbanter - View Single Post - T12 tubes, are direct replacements available?

Andy Wade

On 04/03/2011 17:53, wrote:

Coo, you're right, the tubes in my HF fittings *are* T8 tubes

Be aware that some early HF ballasts (certainly the Philips ones up to
around the late 80s) require special tubes. The correct tubes are
krypton-free triphosphor and are marked with a lower power rating - e.g.
50W for a 5 ft. tube. The tube marking will be something like
TLD50HF/xx, where xx is the colour temperature code. I don't know
whether these tubes are still available.

Later HF ballasts are 'krypton optimised' and use normal tubes, running
at less than the marked wattage.

--
Andy