Sylvania F24T12/HO 35W tube

recently bought, this is my first HO tube in the collection :)

and it has been quite an interesting little tube to experiment with

on the surface it has almost the same specs as a 2ft 40W Tube, 800ma 45V, but due its low resistance 3.6V rapid start cathodes it does not preheat well and will generally cold start

(because at 45V arc voltage, most of the mains voltage is already across the ballast, so when the starter closes to preheat the tube, the voltage across the ballast does not rise all that much so the current does not go up by much and the cathodes dont preheat properly, they need about 1.2A to preheat)

I have it shown here running on my 230V 50Hz 110W F96T12/HO Rapid start ballast, which is a fairly good constant current source so runs this baby F24T12/HO tube just fine as you can see by the lamp meter measuring lamp current :) all US "/HO" tubes run at 800Ma this allows them to have one ballast that can run multiple sizes of tube (all VHO/PG/SHO tubes run at 1.5A and all T12 slimline tubes run at 460Ma for those curious)

(you may notice the normal lamp holders im using, this tube normally has special R17D end caps, but on later Sylvania and Philips tubes like this one they can genetly be popped off to reveal normal G13 end caps and then the special caps can be popped back on if you wish to do so)