Virginian in 1908 - Telephones

NW Mailing List nw-mailing-list at nwhs.org
Wed Oct 8 11:58:21 EDT 2008


Telephone and Telegraph on the same pairs (lines) were not uncommon in the
early days of telephony, along with 3 talking circuits on 2 pair (4 wires)
using what was referred to as a Phantom circuit.
With careful balancing and use of transformers, either voice or telegraph
circuits could be carried when paths were scarce. When distance required
repeaters, amplifiers, (after 1915) when this became practical thanks to Lee
DeForest and his invention of the triode, the circuits would have to be separated
and the signal amplified then recombined.
There are a large number of telephony books from the turn of the (last)
century that cover this in great technical detail.


The above "answer" to the original posting was provided by a knowledgeable,
old friend who has had long experience in electronics and telephone systems.

Don Jackson
NRHS Member
_NWinNscale at aol.com_ (mailto:NWinNscale at aol.com)

_____________________________________


Bluefield Daily Telegraph
September 10, 1908

RUN TRAINS BY "PHONE"
------
Virginian Railway to be Equipped for Double Service Over Same Wire

Since the Virginian railway has commenced to prepare for train service
it has developed that not only is the line to be equipped with telegraphic
wires, but they are to be so arranged that phone service can be used over the
same wires.
The whole line is to be equipped with the double service. By this
system, if the telegraph works badly, the phone can be used.
Another great advantage is that while all employes cannot telegraph
nearly all can talk, and no doubt the line will be so arranged that an engineer
or fireman can make a connection at any point on the line and report to an
office.
This service is used in a small way on several northern railways, but so
far as known the Virginian will be the first to adopt it on the larger scale.
------
[It's good to know that nearly all Virginian employees could talk! Can
anyone explain how this "double service" was accomplished on the same wires
without interference?]

Gordon Hamilton





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