Up until very recently our phone service was provided via an overhead cable from across the street supported on the far end by a power pole. This phone line also carried our broadband internet service. The two adjoining neighbors were also connected in the same manner.
I have long suspected that the broadband services were contributing to the very high noise level on the lower HF bands.

This noise had steadily risen over the years much like the proverbial frog in the pot with the heat slowly applied. I had on a number of occasions turned off our broadband modem to see if there was any change to the noise level, however this did not seem to have any appreciable effect , so as a result of these tests I discounted broadband as the suspect. I had all but given up on the lower bands assuming they had just become a victim of modern civilization. Most of the local amateurs had put the rise in noise down to Plasma TV’s, Switch mode power supplies etc.
I could recall many good contacts on the lower bands back in the early 70’s using low power AM transmitters with other amateurs across the Northern Territory using similar equipment. Last Month our house as well as our neighbors was finally connected to the National Broadband Network with a fibre to the home service. I had the old overhead phone line removed from the house and I could not believe my ears.
The “S “meter on all the lower bands now sits gently on the bottom with the occasional static crash from far away storms lifting it from its rest. So Broadband over phone line can obviously be just as insidious as broadband over power lines. It may be that as the old copper network fell into disrepair the phone lines may not have been as balanced as they once were.
Have a look for me in the coming months down on the lower bands.