Dave,
That's the best way to confirm the "quality" of OSL test loads/terminations.
A few years ago I did a test by calibrating with a known "defective" 50 ohm termination. After calibration I measured the same defective termination. It looked great, but now my known Anrtisu OSL looked terrible.
My point is that almost any calibration made, and then a measurement of the load set used for that calibration will look great, but is it really a true reading? Hardly.
Burt, K6OQK
Dr. David Kirkby wrote:
I don't know if all the NanoVNAs are being shipped with the same open, but
I tested the open shipped with my NanoVNA using an HP 8753ES VNA after
first calibrating with an HP 85052B cal kit. The open did make a *small*
difference - a bit under 1 degree of phase difference at 900 MHz.
It did however cross my mind later that I had a 3.5 mm test port, rather
than SMA, so it would be worth my while repeating with SMA. My own
experience with both 3.5 mm and *SMA* connectors indicates adding *any*
sort of open ended device on the end, does make a measurable difference to
the phase, but I would have thought it pretty insignificant at 900 MHz.
Dave.
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
-=-=-=-=-=-=-=-=-=-
Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California U.S.A.
biwa@...
K6OQK
--
Burt I. Weiner Associates
Broadcast Technical Services
Glendale, CA? U.S.A.
K6OQK
Burt K6OQK