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Thread: NanoVNA

  1. #1

    Default NanoVNA

    Has anyone used the nanoVNA's being sold on amazon? I know there is a large variation of essentially the same device. Some have cases, some have RF shielding, some have more accessories... What Im more interested in is if anyone has used one of these (preferably the shielded variety) and if so how accurate was it? Are they worth the $72 currently being asked? I have the rigexpert aa-170, but I want to expand into UHF capabilities.

  2. #2

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    We have a $60,000 dollar VNA at work, and I have a nano as well. There is no comparison to the capabilities, but the nano is within a few points of accuracy of our R&S. Well worth the $72 asking price for Ham use.

  3. #3

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    I ordered the nanoVNA-F for $126. One issue is that it said it ships from the usa. The tracking said its shipping with DHL but the tracking number is not recognized by the DHL website. The tracking number starts with a 9 so i looked it up on USPS. The number registered but said they have yet to receive the package.

    Unfortunately, when something says it ships from the USA, that actually means it ships from the USA once it gets here from China. This seems to be a common trend lately and I am becoming more and more disappointed with amazon and ebay for allowing this deception to go unchecked.

  4. #4
    gnuuser's Avatar
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    I purchased the NanoVNA
    a while back and watched the you tube videos on it a couple times and read the manual that came with it.
    I havent installed the software in the computer yet and just recently had the chance to use it for tuning an antenna.
    1/4 wave 2 meter ground plane antenna.
    set up and calibration on the touch screen was easy using the guitar pick stylus. and tuning the antenna took about 1 minute of careful trimming on the vertical and radials.
    It was surprisingly easy to use!
    I'm looking forward to studying it in depth a bit later.
    i agree the delay in getting it was a pain in the arse but all in all it was worth it for such a great little portable device.
    too much blood in my caffeine system.

  5. #5

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    I wish it had the option to calibrate to 75ohm. Also, there is a delay feature that doesnt work on mine. Overall, for the price, i am very happy with mine and use it often.

  6. #6
    gnuuser's Avatar
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    all you would need to make a 75 ohm calibration fixture is the end of an old wireless card antenna like the one pictured below and a 75 ohm carbon resistor.( do not use wire-wound resistor) cut the coax about an inch from the knuckle and strip back and solder resistor as close as you can without shorting it out.
    verify with a multi-meter that its within the tolerance of the markings and you good to go!wirant.jpg
    these antennas screw directly on to the vna! click on the link to the picture.
    too much blood in my caffeine system.

  7. #7
    gnuuser's Avatar
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    you can make any size fixture you want for different uses.( I have made different value dummy loads for testing home brew baluns for various transmission lines and cables)
    its not hard to match them once you have specific values. and gives you a myriad assortment of tools to match any antenna to a broadcast system.
    too much blood in my caffeine system.

  8. #8

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    Its not quite that simple. If I wanted to use my nanoVNA on 75ohm coax and calibrate to the end of that coax, I cannot simply attach a 75 ohm load + open + short, hit cal and be done. If I did that, the calibration would put the impedance marker at the center and call it 50ohm. No matter what ohm load you use during the calibration, the dumb thing considers that value 50ohm regardless of what it really is. The only way I have found to use 75ohm coax with the nanoVNA is to calibrate to the nano's port with 50ohm load and aim for the 75ohm point on the graph while tuning whatever is connected to the coax (because when that's a match, the input is 75ohm). When I attempt to measure accurate impedance values through 75ohm coax, I find myself first measuring the coax length then plotting the measured impedance out on a paper chart normalized to 75ohm (so I can use the constant swr circles as a guide) when accounting for the transformative effects of the coax and its loss. My RigExpert can do 75ohm but calibration adjustments to coax ends can only be applied via PC with my model so both options stink for 75ohm use. For 50ohm stuff, I love both analyzers.

    I have a variety of homemade OSL dummy loads already. OSL.png

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