HI,
I use a different approach when I need to know the exact value of inductance or capacitance, I build up a simple jig on a PCB mount connector with a series 50 ohm chip resistor then put the component in series to ground.? With the standard Xc or Xl formula determine the frequency where the value is between 25 to 100 ohms.? I use 1 or 10 MHz and using the formula in reverse extract the true value of the component.? Works very well.? It tells you the net value with all parasitic errors normalize in. So that the VNA reads Z50+/-j.
Mel, K6KBE
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On Saturday, February 13, 2021, 07:49:16 AM PST, Jim Lux <jim@...> wrote:
On 2/13/21 6:39 AM, Ed Krome wrote:
Thank you for the responses. I think I was unclear. What I am trying to understand is how one relates the marked value of a component to what nanovna shows. Using DL5FA¡¯s item 8 inductor, my devices show 700 nH @50khz. But at 100mhz, the reading is 1uH. But the component is speced as 470nH, a value I can¡¯t see anywhere, regardless fir frequency. How should I be reading this thing?
Thanks!
There is always some parasitic C around, which usually "reduces" (or
cancels) some of the inductance - sort of the opposite of what you're
seeing - but in any case, the amount of cancellation you get is
frequency dependent (since the VNA is measuring X, and then converting
that to nH)
Are you allowing for the inductance of the leads going to the
component.? A handy thing is "about 1 nH/mm or 1 uH/meter" for a single
wire.
