I've recently been playing with telephone dials again, and discovered that a handheld dial tester existed which would save faffing around with an oscilloscope. I managed to pick one up on eBay for slightly more than I would have liked to have paid, but it is in perfect condition so I can't complain too much.
Naturally I didn't read the manual and immediately started playing with it, but it turns out it doesn't function quite like how I'd anticipated. Still, I'll probably get some use out of it.
Digit Analyser and Tele 290 test set