TDR display without osciloscope?

Possibly.. fast pulses with eg the Jim Williams design, and you might want a biggish arduino to do the fft's reasonably quickly ......

You can see the system design and description of the aa-30 here:

And the available displays - including TDR - here:

Note that no super fancy hardware is used.

Allan

ps - the processor is an ATmega328 - seen them before?