N2EY wrote:
On Apr 16, 10:20 am, John from Detroit wrote:
N2EY wrote:
Yes, but there were several reasons for the normally-energized series
line systems.
Another thing is that telegraph "lines" might indeed be a single wire..
Using the Ground as the "Return" for the loop
It is my understanding that many of them were. Besides the savings in
wire and insulators, a ground-return system could actually be lower
resistance than a double-wire system if the "made grounds" at the ends
of the lines were very good.
Of course such a line is more vulnerable to noise, but since the wire
telegraph was a digital system the nouse would have to be considerable
to have any effect.
That thing about noise reminded me of a story about a severe magnetic
storm that happened in the 1880s or thereabouts. Currents induced into
telegraph lines were so strong that things caught fire in telegraph
offices as well as simply knocking them offline.
--
David Griffith
--- Put my last name where it belongs