On 17/04/2021 08:29, Brian Gaff (Sofa) wrote:
That sounds like a recipe for disaster to me. Hum induced voltages and
damage putting dangerous voltages up a phone line.
Brian


Not at all. Induction makes little difference to our, notionally
balanced, telephone network and the anchor points are well below the
power cabling. There are several examples of this practice in the
Google Map views the OP offered us.

It is instructive to connect a phone line to a spectrum analyser and
oscilloscope. When looking at either wire there is masses of pickup -
predominantly of the Medium Wave - but some 50Hz, too.
If you then couple both lines via a balun to the spectrum
analyser/oscilloscope, you - thankfully - see way, way, way less
unwanted stuff.

PA