Hi,
I've got no luck finding out how to read markings on pictured part & what would be a replacement part I could buy today.
I'm sure someone with more experience can help?
Thank you!
Lubo
Where is this diode? If this is a repair job, how do you know it's defective?
This is almost certainly not a defective diode.
The shot was taken from a part (a vintage logic analyzer probe) that's supposedly working.
Hello,
the logo seems to be from Unitrode (never knew that they manufactured diodes)
but obviously they sold the diode part to "MicroSemi"
http://www.aufzu.de/semi/unitrode.htmlWith best regards
Andreas
> What probe/analyzer?
A Tektronix P6442 probe for 1230 analyzer.
Sorry for not having been specific enough.
I found a photograph of the PCB from that probe:
https://w140.com/tekwiki/wiki/P6442 I might guess it is a low-voltage zener, being used there to protect the inputs on the MC74HC04 inverter and the MC74HC240 buffer. But without being able to clearly see the tracks, that's a very rough guess.
However, I see what I think are 10 glass diodes on that board, and if they were protection I might expect 16 (one per bit on the logic analyzer).
> What probe/analyzer?
A Tektronix P6442 probe for 1230 analyzer.
Sorry for not having been specific enough.
Maybe Tektronix (like many test equipment manufacturers) has its own part numbering scheme.
So without a "repair/maintenance Handbook" identification may be difficult.
with best regards
Andreas
Given the vintage and the 74HC and 74AC logic, I doubt they are anything special. Probably a switching diode like a IN4148. Trace out the circuit. Is it a bit of M2L?
Tektronix would order parts marked with their own part numbers.
Tektronix diode part numbers are 152-nnnn-rr where the rr is a revision number.
When the whole thing wouldn't fit, they only printed the important part, the middle 4 digits.
So, the complete part number is 152-0574-00.
Now you can go to TekWiki and look in the transistor and diode catalog:
https://w140.com/tekwiki/wiki/Common_Design_Parts_CatalogsOn page 8-7, the spec is given as 120V, 150mA.
One possible replacement would be 1N458A.