[GreenKeys] 1924 Mackay System Video

[Duncan Brown]

Thanks, Harold!  very interesting (wish there had been more views of 
equipment and fewer views of buildings!)

TTY equipment at 40 min. in.

at 40:28 "Punches the message in Morse on this tape"
But at 40:34 shows a five-bit Baudot/Murray code being punched into the 
tape, probably by a Morkrum "GPE/Iron Horse". Tape is being read on a 
standard, parallel input tape reader, essentially the same as used on 
the M14 "TD" (on the M14 tape reader, the "distributor" did the parallel 
to serial conversion).

40:50 "Automatic Receiving" shows a Morkrum M12 without its cover. The 
M12 printer was parallel input with its own motor. This picture shows it 
with the keyboard plug-in, with its own motor. You can just make out the 
goose-neck contacts for the keyboard parallel to serial conversion and 
also a second set of goose-neck contacts for the printer serial to 
parallel conversion.

41:32  This was a synchronous system - how did they maintain 
synchronization?  ( "very carefully")  This was one of the problems with 
the synch. multiplex system - it was difficult to maintain 
synchronization mechanically.

41:50 Morkrum M12 with cover.

42:10 I've never seen anyone  handle a key this way!

Have fun,

Duncan
K2OEQ


On 23-Sep-20 13:45, Harold Hallikainen wrote:
> https://www.youtube.com/watch?v=6fu6-jrzOyM&feature=youtu.be
>
> I got this link from the California Historical Radio Society. This silent
> movie shows the operation of a major telegraph company including views of
> installing and repairing overland wires and undersea cable. Mostly
> straight key telegraphy, but a little printing telegraph.
>
> I thought it was great!
>
> Harold
>
>