The Ely miner. [volume] (Ely, Minn.) 1895-1986, 1926-06-25
WIRED WIRELESS
FOR POWER CO.
MINNESOTA POWER COMPANY
USING POWER WIRES FOR ITS
TRANSACTION OF BUSINESS
BETWEEN STATIONS AS A
"WIRED WIRELESS"

By taking advantage of the latest
development in the radio art, the
Minnesota Power & Light Co. is able
to obtain direct communication be-
tween it's widely separated stations
without building long and expensive
telephone lines. This is accomplished
by the use of carrier current tele-
phony, or, as popularity known,
wired Wireless.
The telephone equipment used at
each station is simply radio broad
casting and receiving set combined,
to- which has been added device for
automatically calling the desired
station. Instead, however, of broad
casting, the message is directed
along the transmission line between
stations by means of coupling con-
densers which connect the telephone
set to the transmission wires. These
condensers, while allowing the car
rier current to pass through freely,
act as insulators to the powercur-
rent and so provide safety for the
telephone user. AS the transmits
sion wires offer less resistance than
the air, to the waves sent out by the
telephone set, practically all the
waves follow the wires to the next
station instead of radiating through
the air, as would be- the case with a
broadcasting station.
/ The entire sequence of operation
in communicating with the carrier
current telephones is almost ident
zeal to that of using the automatic
telephone which is now being in
stalled in many of the larger cities
When the operator at the calling
station lifts his receiver off the hook,
the sending apparatus is automat-
ically started up ready to send
| message. He then calls the desired
station by dialing the code number
of that station. This operation
causes series of Impulses to be
sent out to which, relays at the par
ticular station called will respond
and operate a signal bell. The
/ operator being called answers in the
usual manner after lifting his re-
ceiver off the hook, which also starts
up his sending apparatus, and the
AS but one frequency is used,
conversation is completed.
both for talking and listening, an
ingenious device is introduced to
prevent the speaker listening to him
self in his receiver and at the same
time allows him to hear the other
party speak if he wishes to cut in.
At present the company has this
| type of telephone installed in its
sub-station at Nashwauk, Mimi, on
the Mesabi range and in it's hydro
electric stations at Thompson and
Blanchard. While the usual wire
telephone system will probably con-
tinue for some time to be used be-
tween nearby points, the carrier
current SYSTEM is proving very salts
| factory for long distance communi-
cation, and it is quite possible that
| with further development and reduc-
ton in first cost application can be
made to communication over shorter
distances. Not only does the carrier
current save the cost of building
long telephone lines but it has been
found that communication can be
maintained through storms which
have in many cases put the wire lines
out of service and it is of course
during just such periods that conf
mnication is most ecessary-Skil.
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