开云体育

Hi All,

I made some good progress with the ECal controller replacement. It's
effectively an 85097A but with opensource software using scikit-rf.
If you're into python you can check out the code on github:
OwlvilleWol/VnaCalWizard (github.com)
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I plan to post my hardware implementation too, but I have to work on the
docs and I'm not overly happy with it anyway.

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I wanted to be smart and use an Ftdi usb device instead of an arduino to
avoid having to maintain two sets of code, but I regret it now as the
solution is not as elegant as I hoped for and the port direction changes
of the Ftdi chip make EEPROM readouts very slow.
The program is written so that that has to be done only once though,
then, if present, standards data are loaded from touchstone files on
disc. (This could be a way to re-characterize the ECal devices without
having to write data back to them.)

I can cal my 8720C with it, although the top-level functions are still
missing. I'll be finishing that and add a few features such as multiple
ECal units covering the frequency range and pre-characterized adapter
(gender changer) removal.
My python is not very good so it's rough around the edges, but I tried
to separate functional blocks for easy additions/modification/reuse.
E.g. the ECal class has a separate hardware abstraction layer so the
Ftdi based interface could be easily replaced with something else, while
keeping everything above intact.

Let me know if you're interested in replicating and
testing/using/improving this.