First Attempt at Creating a Time-Domain Reflector (TDR) Circuit

May 26, 2018 • 1 min read • Updated May 26, 2018

I’ve just had my first go at creating a Time-Domain Reflector (TDR) circuit to measure

the length of a coaxial cable. The circuit uses a 74AC14 Schmitt trigger inverter, as outlined in the W2AEW YouTube video. 📡

This was an interesting project, as it’s an excellent way to measure the length of coax cables and detect any faults or impedance mismatches. The TDR works by sending a fast pulse down the cable and measuring the reflection, which can then be used to calculate the distance to any discontinuities or the total length of the cable.

Helpful Resources:

W2AEW’s YouTube Video on TDR Circuit – A great step-by-step guide for building the circuit.
Time-Domain Reflectometry Explained – A basic explanation of how TDR works and how it can be used.
74AC14 Schmitt Trigger Inverter Datasheet – Technical details on the Schmitt trigger used in the circuit.

I’m really enjoying the W2AEW channel and highly recommend it to anyone interested in RF and electronics. I’ll be experimenting more with this setup soon! If you’ve worked with TDR circuits before, feel free to share any tips or experiences!