Media for ANCIENT telephone transmission [telecom]

Cast your mind back to the first decade of the last century, no computers, no transistors, no valves.

I'm mainly interested in the situation in Australia, which may or may not be the same as the US/UK.

The historians tell me that 600 mile lines were common, and that they carried multiple conversations using Frequency Division Multiplexing.

Does someone want to have a go at explaining how this could work?

- Without the afore mentioned technology, how do you modulate and combine the conversations?

- Without amplifiers, how do you handle attenuation?

- How do you separate the conversations? Surely banks of unbuffered tuned circuits would interfere with each other.

- Presumably, unlike local loops, these long lines only carried AC so how was call management/signalling achieved?

***** Moderator's Note *****

Vacuum tubes are called "Valves" in Australia.

Bill Horne Moderator