[GreenKeys] East Wire and West Wire?

[Jim Haynes]

In telegraphy you often have a wire that loops through a station.
So one direction from the station is arbitrarily called East and
the opposite direction is called West.  I've also seen North and
South used in some Western Union circuits and in railroad usage.

Also in telephone carrier systems, where a different frequency
is used in each direction, a carrier terminal will be identified
as East or West depending on which frequency is used in which
direction.  Likewise in a two-wire system with repeaters the
two ends of the repeater will be labelled East and West, although
in this case it doesn't matter which end is which since it
repeats the same frequencies in both directions.

Since the designations are arbitrary you'll have circuts labelled
East and West even if the wire runs directly north and south.  And
occasionally due to strange circuit geography you'll find a circuit
labelled East that actually leaves the west side of the office before
going toward the East.