thanks for the demonstration. I am getting my nanoVNA-F setup for TDR measurements presently so this has been helpful. One caveat; when measuring antennas VSWR or cable runs outside ,to short the cable first before hooking anything up to the VNA to remove any static charge as the Nano-VNA does NOT like static at all. 73, Jim AC0E DM97nx
Thanks Jim, a good point. As the coax was connected to my active loop there would have been no static charge in this case, but an unterminated cable could build up a charge as its acting as a high voltage capacitor. best wishes nick
TDR is very useful. When I was in Air Force stationed in S Korea we had problem with an air dialectic cable feeding an HF Log Periodic Antenna. It had a short in it somewhere. We used a TDR to locate the short. It was inside a piece of 6” diameter pipe that spanned a drainage ditch. The pipe had a sag in the middle and water had settled in the area of the pipe that had the sag. It was winter in Korea and apparently due to a series of freezing and thawing, the expansion of the ice as it froze and thawed has crushed the Air Dielectric cable allowing the center conductor to contact the outer conductor and shorted out the cable. I had to build a fire under the pipe to thaw the pipe enough to pull the damaged cable out of the pipe. We ended up re-routing the conduit to ensure it had a slope that ensured it would drain instead of holding water.
Hello, this is the second video that I see on your website about nanovna saa-2n and they are really magnificent, I also bought this type of nanovna and the documentation is scarce because you do me a great favor to upload all the possible videos about the different uses and If you can upload the address of the document you mentioned, I don't speak English, I only speak Spanish but I use google translators and subtitles, thank you very much.
Here is link to manual www.google.com/url?sa=t&source=web&rct=j&url=uglyduck.vajn.icu/PDF/vna/NanoVNA_GUI_UG1101.pdf&ved=2ahUKEwiFwfCC093wAhWi2uAKHXy-BAMQFjAAegQIAxAC&usg=AOvVaw1R8dBsiG4tq5tG5PsSRLQE
HI Nick. Thanks for TDR measurements. Used the technique, when working professionaly. Good for finding discontinuities throgh bulkheads, connectors, etc.As well as your cable length measurements. I bought a single port vna, sometime ago, Wish I has waited for Nano VNA's. Thanks for the 1n5408 diodes, Done the job , Were you able to salvage any good bits from the SS amp ? 73 Mike.
I remember using a pulse generator & scope as a t d r, send a pulse down the coax & measure the time for the reflected pulse to come back. Not very accurate. The circuit board from the amp is in a box with many others which I go to when I can't find a new component, so it won't be wasted, best wishes nick
