Siemens.
This is for a dual jfet 2N5566. Did Siemens ever make such a transistor?
Jaycee - That is exactly the marking on this 2N5566 jfet!
Tommy1000 - Thanks! The jfets in question are dated from 1988 and they have the Siemens' symbol as in Jaycees post...
Which one - Jaycee's post has 6 markings...
Is it a Siemens/Halske one?
jan didden