The 12W Circolux - EL was marketed only a very short time. Here you find it the catalogue from 1985, page 21 (in German) language:
http://www.lamptech.co.uk/Documents/Catalogues/Osram%20-%20Catalogue%20-%201985%20DE.pdf
Thanks for the link! I didn't know they were so short on the market.
That makes me wonder when the 25W version was introduced.
Wonder where to get the FC6t9 tube in Europe, I would like to get some spare tubes for my Circolux...
I could not find them here in the EU so I got one from the US.
For me it was an obscure tube which I had never seen. The only versions I
knew back then were 22W, 32W and 40W. Then I discovered the 20W FC6t9 tube.
But it is not clear to me what Osram did in the 12W version.
Is that a special tube, or just the standard 20W version on lower power?
Personally I think the latter. But I'm not sure...
All three 12W lamps are working. But they have a high mileage...
Here is my repaired 25W version on youtube...
https://youtu.be/_tFT4HIgscY