Strange TD in 067-0587-01

Albert Otten

I try to resurrect a calibration fixture 067-0587-01. Some parts have been removed in the passed, along with a TD CR280 which I removed myself but kept apart all the time. Now I reinserted that TD but is refused to switch. With my 576 I discovered that the polarity of this TD was opposite to what I expected for a DO-17. With a magnifier glass I saw that the arrow indeed pointed towards the isolated lead instead of the mass lead. I have never seen this before. The TD in my other calibration fixture has the "normal" arrow direction.
Further the marking is 152-199 without any doubt, while the 152-0199-00 is listed as a rectifier diode.
The manual mentions 152-0177-00.
Is the other arrow direction indeed unusual?