- 2023
- Jun
- 23
Random board shot: AT&T PBX Surge Suppressor
This board containing a rather simplistic transient suppression circuit is the “AT&T Model 145 Transient Voltage Surge Protector” - nothing more than 3 Metal-Oxide Varistors of the same kind you’d find in a cheap power strip from the discount store. I suppose the giant box the thing is in and the red lamp on the front make up for the fact that this thing isn’t going to do diddle other than make some (contained) fire in an emergency. There’s no other filtering, and MOVs are a one-and-done device.
These were provided with AT&T network equipment, in this case a Merlin 820D2 4 line to 20 phone commercial PBX. I can’t complain, however, the device this protected was just recently turned off. Ma Bell made it to last 40 years, and it pretty much got there.
That’s not why I’m posting this, however. Of note is the orange Textolite “T”, once again indicating how far the GE Coshocton manufacturing plant reached over the years.
Another reminder of the past packed in a little box.