Collaborate Disseminate
How do you know that your patch cables are good? For simple jumper wires, a multimeter is about all you need to know for sure. But things can get weird …read more Continue reading Making Sure Your Patch Cables Are Ready for RF Work
“Time-domain reflectometry” sure sounds like something that needs racks of expensive equipment to accomplish. In reality, TDR is just measuring the time between injecting a pulse into a cable and receiving its echo, either from the other end of the cable or from some fault or defect along the way. …read more
Continue reading Dead Simple Time-Domain Reflectometry with Just a Battery and an Oscilloscope
A time domain reflectometer, or TDR, is an essential piece of test gear when working on long cables. The idea is simple: send a pulse down the cable and listen for the reflection from the far end. The catch is that pesky universal constant, the speed of light.
The reason the speed of light is an issue is that, in a traditional system, the pulse needs to be complete before the reflection. Also, time is resolution, so a 1 GHz sampling rate provides a resolution of about 10 centimeters. [Krampmeier] has a different design. He sends variable length pulses and …read more
