Ok I’ll bite…

37 miles?!? Why??

Land-mobile radio stuff. Analog, voice communication.

Our sales guy had sold a remote node for a voter system to improve receive coverage for a central dispatch system. (Signal-to-noise voters are pretty neat: They can continuously compare two or more related audio signals and [ideally!] pick the one that is best for use while discarding the others.)

That node wasn't all that far away as the crow flies, but it was a very long way out in telephone cabling miles. It spread across two different telco LATAs.

So we rented this very long series of bits of wire held together by scotchloks and punch blocks and whatever else in telephone world to use, and we used it. It was not a conditioned circuit: Just wire.

The specific endpoints of that wire were kind of neat, too: There was some basic EQ that could be used to help compensate, and (IIRC) some impedance adjustment to dial in the circuit itself.

And there was a continuous pilot tone used to set gain: Apparently, when wire gets really long like that, atmospheric conditions can dynamically change its attenuation.

Putting a pilot tone near the middle of the voice range (to be notched it out later) and using its level to set gain helps to improve consistency.

That wireline stuff all worked pretty well.

(The remote node was ultimately a bust. The sales guy also tried to cram too much shit into one feedline and antenna, and the gear to combine and separate all of those signals ate too much energy to make any of it an improvement over doing nothing at all.

Which is... well, that's exactly what the engineering told him would happen, but he did it anyway.

No part of this was inexpensive.)