A true TDR sends out a short pulse and looks at the time it takes for that pulse to return.
The NANO VNA sweeps frequency and notes where the frequency when reflected impedance approaches Infinity and Zero Ohms.? ? ?Different resonate points? ?Then calculates the length of the line from it's resonate points.Same result, different methods.??
I own 3 TDR's and a good TDR will show you where along the line the coax has been stepped on, has a defect, or even where some water has leaked into the line.? The Nano is not going to get to those levels, but what do you expect for 20 dB less money?? ??
The Nano works in the Frequency Domain, a TDR? (Time Domain Reflectometer) works in the Time Domain.So technically the Nano is not a TDR.? ? But gives a similar answer.? ? ? ?Kent WA5VJB? For many years an Applications Engineer with Tektronix.?
On Tuesday, June 20, 2023 at 07:16:11 AM CDT, DougVL <k8rftradio@...> wro On Mon, Jun 19, 2023 at 01:32 PM, Stan Dye wrote:
recent firmware has a
Cable Measure function built in. Have you tried that?
It's a wonderful, very useful feature.? Very quick and easy to use, no other settings to make.
It does use a different method than TDR, and is explained in the info for the first firmware version that includes the feature. (I don't have that text available to quote here, though - sorry!)
--
Doug, K8RFT
