Hello there. I have had this lamp for almost a year now. It is a very old circular glass fluorescent light fixture dating back to 1962. The ballast has seemingly been replaced. However it has a very unusual style of bulb. It has a 65w/80w circular lamp with two separate G13 bases instead of a typical G10q base. It is also T12 in width which is very unusual. I’ve never seen this sort of lamp before and I can’t find any information about it. If anyone has any information about this lamp please let me know as it would be very helpful.

Hello there. I have had this lamp for almost a year now. It is a very old circular glass fluorescent light fixture dating back to 1962. The ballast has seemingly been replaced. However it has a very unusual style of bulb. It has a 65w/80w circular lamp with two separate G13 bases instead of a typical G10q base. It is also T12 in width which is very unusual. I’ve never seen this sort of lamp before and I can’t find any information about it. If anyone has any information about this lamp please let me know as it would be very helpful.

Awesome find! I have been looking for one of those for years and years now! theres a few collectors who have examples, but I have never been able to find one sadly

https://www.lighting-gallery.net/gallery/displayimage.php?pos=-76898

https://www.lighting-gallery.net/gallery/displayimage.php?pos=-173575

https://www.lighting-gallery.net/gallery/displayimage.php?pos=-183835

there is sadly not much information out there about them exactly, the earliest examples had Bayonet end caps but most have bipin caps like yours, I was told many many years ago that the coal-board used these tubes in some application or another, but I have nothing to substantiate that, they are in general quite the mysterious tube

the company Bright Light Lamps or Long Lamps (not sure if they where 1 and the same or 2 separate companies) specialised in making custom/weird fluorescent tubes

https://www.lighting-gallery.net/gallery/displayimage.php?pos=-204487

they also made another famous but just as mysterious "W" tube

https://www.lighting-gallery.net/gallery/displayimage.php?pos=-137103

Thank you this is really helpful. The tube in this lamp is original the 60s and still works perfectly. Hopefully it’ll work for another 30 years!

I highly recommend only running this fixture occasionally due to the extreme rarity of these circular fluorescent lamps.

As of today, the lamp in the fixture is working fine without any issues. Unfortunately the fixture is located in the downstairs corridor of my home right beside the stairs and it is used every day out of my control. What I am planning to do is to replace the lamp that is currently in the fixture with a 60W circline as this is compatible with the new ballast I fitted earlier this year, however I don’t know when I will be able to do this. Also, since the 80s, circlines have become much less popular in the UK than they were anywhere else most likely due to the 2D lamp, invented by Thorn in 1981, being favoured. They are also pretty hard to find at a reasonable cost. I will try to replace the lamp as soon as I can, but hopefully by the time I have the parts to replace it (I also need a new base for it), the old lamp will still work.

Can you put in there a 40W circline and ballast ? (Dont remove the 65W ballast, wire it back in once you find a 60W circline)

Unfortunately I don’t have a 40W ballast spare at the moment.

40W LED circline with no ballast ? (Not the greatest lighting, but as a temporary step)

Unfortunately I don’t have this either. I will most likely buy a 60W circline as the new 58W ballast is already there. They are pricey but there is this shop I know of that has all sorts of old fluorescent tubes, and I might go and check there again to see if they have any circlines.