Are there trimmer caps on the sides of the unit. If soback out the screws.
This will reduce the minimum capacitance.
*Clyde K. Spencer*
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On Mon, Nov 22, 2021 at 10:12 AM Joe WB9SBD <nss@...> wrote:
I have a NanoVNA-H4
Using it I am trying to measure the capacitance of a large variable Cap.
I have read about as much as I can find, and watched dozens of You-Tube
videos.
My Test lead is one of those 6" long pieces of coax that comes with the
unit.
It ends in a very short like 1" long leads with micro alligator clips on
the ends.
Now i do the whole calibrate thing and all that,
and simply connect the leads on each section of the cap as close
together as possible.
I have two caps, Manufacturer specs say
250 to 40 pf
and
170 to 20 pf
Using the VNA when I measure them the max "C" values are dead on, 249
and 169 pf
But the min's are double what they are supposed to be, the 20 measures at
40
and the 40 measures as 80.
Not sure why. Or if I am doing something wrong when measuring these caps.
Anyone?
Joe WB9SBD
