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VNA LOAD-Key

Posted: Thu Jun 07, 2018 7:28 pm
by drdieter
Hi VNA experts,

I did my first steps with Pavel's VNA software . With a bridge bought at eBay it seems to work fine.
After calibration with OPEN-key and SHORT-key the Impedance diagramm shows what is expected for the DUT.

What I do not understand is the function of the key load. It seems that it's flats the curve on the load/ref input to 50 Ohms??? (I have 50 ohms attached there.)

Could you please give me a hint what that key does. Or has somebody a manual where I can read about. Searching for that was'nt successful.

Dieter

Re: VNA LOAD-Key

Posted: Fri Jun 08, 2018 6:56 am
by pavel
Hi Dieter,

The LOAD calibration should be done with a 50 Ohm load. The results of this calibration are used for the impedance calculation. Here is a link to the corresponding code:
https://github.com/pavel-demin/red-pita ... na.py#L701

Best regards,

Pavel

Re: VNA LOAD-Key

Posted: Fri Jun 08, 2018 10:51 am
by drdieter
Hi Pavel
many thx for the quick answer.
So, I did it correct and will deepen into the code.

And it's a great app you developped.
Dieter