Beware of cheap underperforming clones

As of 2022 there are many badly performing clones on the market. V2/3GHz NanoVNA uses parts like ADF4350 and AD8342 which are costly and clones have been cutting costs by using salvaged or reject parts.

See official store and look for V2 Plus4/V2 Plus4 Pro versions only to avoid getting a bad clone. We have stopped selling V2.2 versions since October 2020, so all V2 hardware that are not Plus or Plus4 are not made by us and we can not guarantee performance.

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Measuring chokes...


DawidB 2022/08/09 05:00

HI,

I wanna measure chokes that I've build, i know that it should use 2 port calibration, but I have problem to find soultion how to build proper probes for such measurement.

Thanks for any information

Hank Hamner 2022/08/09 19:08

Dawid,

Attached is a photo of a setup I use to measure common mode chokes for HF.
This would not work for GHz frequencies. The key is calibration. I use
two SMD 100 ohm resistors soldered in parallel as shown for the load (you
need two of these) and isolation calibrations and the short copper wires
for the short and through calibrations. Push the wires into the fixtures
as far as you can to reduce the wire inductances messing up your
calibration.

As you can see I was testing a two core FT-240-43 ferrite wound with 9
turns of magnet wire. This is not a final choke but a simulation. The
display on the NanoVNA Saver software looks much better. I picked up the
very high quality Rosenberger coax leads from a hamfest meeting a few weeks
ago for $1.25 each.

Good luck!

Hank



On Tue, Aug 9, 2022 at 12:22 PM DawidB <dwadi84@gmail.com> wrote:

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