Here is a 6C33C-B vacuum tube, a tube which is found in, say, Lamm ML1.1 and ML2.1 amplifiers.
In trying to accurately identify this tube, one might reasonably try and describe all information printed on it to somebody, say, over the phone.
This particular tube then, is the “6C33C-B ‘phallic symbol’ 81 with an OTX 7 in a diamond” tube.
At least, that is what I overheard people talking and laughing and wondering about as I was, as usual, hard at work in my office. ๐
[OK, Neli wants me to remind everybody that there is something on both sides of the phallic symbol….
On the left is the month and on the right is the year of manufacture.
๐
Me? I’m calling it a ‘rocket ship’].