HISTORY:
At the beginning of my career in electronics, many moons ago, I worked in the telephony industry in NZ. After a few years in the tech side (Fault Control Centre & Exchange techie) I could see the rapid advancement of technology would mean the end of my job as I knew it and left that industry.
However the flame has always burned for all things relating to telephones, both at the subscriber, exchange and all things in between (even loading coils!) So whenever I crossed paths with some telephone equipment, I 'collected' it.
The last few years have been cleanup time with a LOT of the gear finding new owners and now I am approaching the end of my telephone gear collection but I still find some 'dribs n drabs' of equipment - this subscriber instrument is one of those items.
Before it underwent 'the operation' on the workshop bench, this was a type 746 subscriber telephone BUT the rotary dial and case had already been donated to other equipment and I was now left with the 'carcass' showing in one of the phototgraphs.
To the best of my knowledge, this would appear to be a British made instrument not local to Australia or NZ although I think STC Australia had a hand in similar equipment. In my description of this telephone component, I provide all of the identification markings I can see so that you can make sure this component will suit your own telephone.
Obviously this component is aimed at those who share a similar passion for those good ol' days of 2 wire lines, A & B wires, 'boxes' and 'cabinets' and who could forget those aerial lines (meaning wires up in the air between poles) with the glass or porcelain insulators? In the exchange, that never ending sound of the uniselectors and switches moving all the time, especially when the local radio station had a 'call in' competition ... those were the days
Enough of the background to this component, time to tell you all about it ...
If this component from the 746 instrument isn't what you are looking for ... try searching HERE
STC (STANDARD TELEPHONE & CABLES) UK - Subscriber Telephone Component
Removed from what was left of a BPO type 746 instrument (see photograph prior to the 'operation')
Component: Carbon granule transmitter capsule
Type: 16
Actual part numbers (stamped into the rear): 4050E 16 S.T.C 74 2
Screw terminations (2)
Plastic body - Aluminium face
Dimensions: 57mm diameter x 23.5mm height
TESTING:
I have a simple test circuit made so I could check for audio from this transmitter - the transmitter works!
I did not use the transmitter extensively over a long period of time so I cannot comment on the common issues with these i.e frying or plain old noise. This type of noise issue was the most common cause for replacement back in those days, they rarely just "failed" and were never intended to be serviced (sealed unit) so they were just replacement by the linesman. These were designed with a life of only 2 years! but many still perform fine after 40+ years, it all depends upon the environment they were used in and how many of the subscribers 'dribbled' into the transmitter!
COSMETIC CONDITION:
USED
CLEAN
STERILISED (Diluted Iso Alcohol solution on the wipes to kill off any 'nasties')
NO damage to the body or the Aluminium face
Screw terminals are also undamaged
I have now placed this transmitter into a sealed clear plastic packet, waiting to bring another telephone instrument to life!
