I hate to admit it, but the measurements were made using the HP 8753C -
just because I'm far more familiar with that piece of test equipment. I
certainly could have used the NANOs. My lab is configured for the HP
equipment. Forgive me......?......please?
Dave - W?LEV
On Fri, Feb 26, 2021 at 6:29 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:
On Fri, Feb 26, 2021 at 05:33 AM, WB2UAQ wrote:
Don't know how you applied the Nanovna but for impedances above a few
hundred
ohms S11 accuracy falls apart. I have an 18 month old nano so maybe accy
improvements have been made since then. But if the resistance bridge is
still in use I don't think there can be any improvements.
In a recent post I documented how It is possible to measure a 1000 ohm
resistor to within 1% and a 3000 ohm resistor to within 3% using a
NanoVNA-H4 and a suitable test jig. The graphs are attached and here is
the link to the post.
/g/nanovna-users/message/20941
Some months ago I did a measurement on a small ceramic capacitor marked 10
pF on an older NanoVNA-H. Reactance was measured in the thousands of ohms
and still gave a good estimate of the capacitor value. Two graphs are
attached - one is the measured reactance and the other is the equivalent
capacitance using the formula C = 1/(2*pi*freq*Xc).
So it is possible to measure high impedance if a proper test jig is used.
Roger
--
*Dave - W?LEV*
*Just Let Darwin Work*
