I recall (but can't cite the source) that the New York Philharmonic AM
program was sent cross-country using 4 linked land lines. I don't know how
it worked, but it made the frequency response and dynamic range in, say,
California, much better than if only one line was used.
When considering multiple sources of the same broadcast for dubbing, a
really important factor to determine is if the audio was taken down before
being sent to the transmitter or after. It's not only the tampering at the
transmitter but also the atmospherics.
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]] On Behalf Of Michael Shoshani
Sent: Wednesday, September 30, 2015 12:16 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Radio sound
To address Dave Burnham's original post, which I somehow missed:
> Theoretically AM broadcasting should be capable of a 5k bandwidth.
According to historian Fred Krock, up until the mid-1940s, network radio
actually carried a maximum of 8k bandwidth. Station crowding wasn't as much
of a problem as it is today, I suppose.