Hi, I was wondering if anybody might know what ballast would work best with F13T8 tubes? I don`t really want to use 13-22 watt chokes because it will overdrive the tubes and the ballast will run hot. Maybe a 13 watt PL ballast?

I don't have data on the electrical characteristics of the F13T8, but I would personally be surprised if a standard 14/15/20 choke drove it even near full power. I would guess the arc voltage is similar to the F14T12, so such a choke should run within specifications and not overheat.

The specifications for the Advance LO-13-22 (a choke rated for the F13T8) states that current is 0.34A with said lamp, and the lamp is run at 91% power at said current. This would mean that the F13T8 is around 40V by 0.375A. Advance's ballast specifications are usually slightly inaccurate, but this is a good starting point.

Those specs would mean that a standard 14/15/20 choke shouldn't overheat (an F14T12 is 43V, so not much lower), and most chokes shouldn't overdrive it (my own 14/15/20 choke does 0.35A on an F14T12).

A mild overdrive won't hurt it for a test, so what you can do is throw it on some choke, measure the arc voltage, divide 13 by that arc voltage, then divide the result by 0.85 (a constant which I've found to reliably compensate for a discharge lamp's power factor). The result will be the current.

When I get my lamp, I'll put it through my usual thorough testing to determine the electrical parameters.

I have both a 13-22 watt and a 13 watt PL choke, I guess I`ll just have to test them both with the lamp