Virginian in 1908 - Telephones

[NW Mailing List]

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





**************New MapQuest Local shows what's happening at your destination.  
Dining, Movies, Events, News & more. Try it out!      
(http://local.mapquest.com/?ncid=emlcntnew00000001)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://six.pairlist.net/pipermail/nw-mailing-list/attachments/20081008/e66717ea/attachment.htm>