Around 2000, I saw a crew pulling new phone lines through the neighborhood because everybody was getting a second line and they were running out, but even after switching to the new copper, we were still stuck at 26400. 20+ years later, it looks like 25/5 ADSL is now available at that address, so the new copper wasn't a complete waste.
More than one A-to-D conversion would knock it down to no more than 33.6. Pair gain units would cause problems. Bridge taps and load coils could also be problematic, but that was much more of a concern on DSL. Older amplifiers had very narrow filters and would also cause slow speeds. Echo cancellation hardware would ignore the in-band signal to get out of the way and cause problems.
As there was no legal compulsion to get them to act Bellsouth wouldn't do anything to help slow connect speeds for internet dialup. The trick was to lie and say you were having problems sending a fax, then they were required to act. They wouldn't even worry about testing first, as it was quicker to just re-engineer the line to the best practices of the day.
I worked tech support at an ISP. Occasionally customers would call in from their brand new subdivision to complain about our crummy service. “This house is brand new and we only get 26.4. What’s wrong with your system?”
And then I had the satisfaction of explaining that Ma Bell cheaper out and used pair gains to build out their block cheaply. Sorry, call them to complain, or move.
