"COLIN LAMB" wrote in message
...
I never thought about this until the matter came up in the
HQ-145 thread, but what was the process of sending messages
over the telegraph lines?

Suppose I was in a small town in Oregon and wanted to send
a message to a small town in Nebraska? Is the message
"broadcast", or does it go to a clearinghouse? Can anyone
on the "wire" listen in? Are there relays?

I have been a ham for almost 50 years and I have no clue.
There must be some OT who are just waiting to tell me, or
know a good website.

Thanks and 73, Colin K7FM
I think it depended on how complex the telegraph system
was. There are some early telegraph handbooks available at
Google Books. Most of the stuff that has been scanned and
can be downloaded complete (rather than just sample pages)
was published before 1900 to avoid copyright problems and
some is not very well scanned, but its available.
Briefly, there was a clearing house or message center on
larger systems (like Western Union) and most simpler
telegraph circuits were "party lines" will all instruments
connected in series. That's the reason telegraph keys have
circuit closers on them. Any transmission from any station
was heard at all of them. If an operator sent a message and
forgot to close the circuit the whole thing was down until
it was closed again. There was an alternative system with no
steady DC in the lines but I don't think that was used much
in the US. Seach around the telegraphy books for more.


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Richard Knoppow
Los Angeles, CA, USA