G.P.O. GMT 34 and Clock 36

Used by the British G.P.O for many years, this is a Master clock No. 36, being run from a clock unit GMT 34. These would run the slave clocks in a building plus the timing for Strowger telephone exchanges.

Category:

Science & Technology

Tags:

• clock
• 36
• gmt
• 34
• pulse
• slave
• master

[BrentAudi]

This is awesome!

[xenon53827]

@BrentAudi thanks!

There is more of this clock system, search for...

G.P.O. Pulse clock system tour

[xenon53827]

This clock was rescued from a non-director exchange.

[djkavika]

Nice. I caught the last of this stuff when I was little in the early 80's at the local exchange. What year is this from?

[xenon53827]

The equipment is from the 1950-60's, but I shot the video in the summer of 2009. I saved a lot of the old stuff and am still in the process of getting the rest of the system up and running.

[RODALCO2007]

Excellent video, thanks for putting it up.

Especially good to see the 50 Volts 1, 6 and 30 seconds relays which you normally not see.

[xenon53827]

to be accurate, all the 3000 type relays are 24 Volts, every bit of exchange stuff had a small spool resistor in it, except small branch exchanges that ran on 24V.

but it is nice to see them all working correctly and I am glad that you enjoyed the vid.

[BullfrogFM]

I am glad some of these clocks survived. Any non director exchanges I have visited has a master clock. I can't quite remember where the UAX exchanges got their timing from. maybe from pairs from a main exchange or from an internal timing relay set using uni selectors. One of the main reasons for the pulse generation I believe, was to provide signaling for the Subscribers meter. Each subscriber has a analog counter assigned to the telephone number and was read quarterly for billing purposes.

[Madness832]

Talk about an amazing piece of electromechanical engineering!