My favorite TDR is made by "Billy Bob". It's neither digital or waveform, it's audible. Just hook your test leads to the cable in question and it will announce "Dog wont hunt" or "That's a good-un"... it aint a whole lot of help when precision is required but when you're just gonna fault the span and send a contractor to replace it, it's adequate... Ask any Adelphia tech ya happen to see, "what's the best TDR?" "Billy Bob, yes-sireee"...