That's a nice write-up!
I've also used the Spectrum analyser / tracking generator approach - I
find the real-time plot instructive for seeing how the SRF swings around
with changed lead "dressing" and with "proximity effects". I like to
have the choke "dangling" in free space if I can - getting it close to
the test kit makes a big difference on some of the higher-Q chokes.
By the way, your write-up talks about a 6 core choke, but I see only 5
cores in the photos; am I losing the ability to count, or did you drop
one along the way :)
On 23/04/2012 15:32, Tod Olson wrote:
> What measurement equipment and set up did you use to determine the Z of the
> chokes that you built? Do you have any pictures of the measurement setup? Do
> you have any graphs or data beyond the (f,Z) points in your email you might
> be willing to share?
> I made some indirect measurements in 2010 of Z of the larger diameter core
> chokes as a function of frequency . The write up is located at
> It might be interesting to perform the same measurements with the same set
> up using the smaller diameter cores.
> Tod, K0TO
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