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
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Measuring chokes...
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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