[GreenKeys] Fanout Device

[Jim Haynes]

Teletype wasn't in the transmission business, so they would not have made
such a thing.

Except that in the factory where they were running a lot of machines from
a quick brown fox generator they had a test setup with vacuum tubes
driving the machines.  Something like 6W6 or maybe 25L6.  If you used
25L6 you could run five of them with the heaters in series and not need
a filament transformer.

But in the field, as someone mentioned the polar relay was often used,
and for receive-only situations they could use polar transmission to
improve signal quality.  But it's also true that when a lot of machines
are to be run from one signal source, the circuit is actually made up
of pieces of circuits connected together at the telephone or telegraph
office.  They used things called "hub repeaters" or "network entry
repeaters" to make a bunch of circuit pieces act as if they were one
long wire looping through all the customer's premises.