Just wondering, I have two of the old style SL lamps. A 9W and a 18W. I call them generation 0, because the construction is different compared to the 1982 (called generation 1) and later models. In generation 0 the starter is placed between the electrodes of the lamp instead of in the base of the lamp like all 1982 and later models.

Here you can see them...

Philips SL18 December 1980
https://www.lighting-gallery.net/gallery/displayimage.php?album=8085&pos=1&pid=235836

Philips SL9 September 1981
https://www.lighting-gallery.net/gallery/displayimage.php?album=8085&pos=2&pid=235834

Now my question, is this old construction ever used for the 13W and 25W models? I can't find any reference about these models in an early construction.

Regards, Roland

Hi, I'm not sure if I've ever seen an SL bulb with the starter between the tubes but this is good info! Thanks!