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The software that comes with the AIM4170/4300 can automatically measure crystals.? I have designed about 20 different crystal filters? using this software and the results are virtually perfect with

Hi Alan Oristo just told QRP has the solution Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] <[email protected]> P? vegne af Alan G3XAQ Sendt: 29. oktober 2019

Hi Alan Yes I missed that point and agree 1Hz step is a must. But I have seen mentioned in a posting frequency steps of 1Hz for a special firmware but when and from whom I do not recall Kind regards

you can find firmware here: https://github.com/qrp73/NanoVNA-Q/releases Just tested 0.4.2 supports 1 Hz steps. Frequency steps smaller than 1 Hz is not supported, because frequency is represented with

All the NanoVNA devices use resistive touchscreen devices so it is irrelevant if you leave it on or take it off. However, replacing it with a real screen protector is always a good idea.? ... Larry

This is really a 2nd order polynomial...it seems to be entirely adequate. Higher order (x^3...) polynomials can be made to fit almost anything in a strict range, but IMO much above 3rd is not

More points means more long measurement and more high probability of some interference spike. I think may be there is need for a median filtering, but there is too small memory in order to do median

yes, it supports 1 Hz step, also there is fixed frequency rounding error and it measure exactly these frequencies which are requested. With old firmware versions you will get random frequency errors

At least QRP's recent firmwares accept 1Hz steps, e.g.: scan usage: scan {start(Hz)} {stop(Hz)} [points] scan 10000 10100 100 frequencies 10000 10001 10002 10003 ... 10098 10100

Different types of protectors exist for plastic screens: One is just meant to protect the plastic screen surface from scratches (and fingerprints) while being handled during manufacturing and

.. assuming independent random noise. I told gnuplot to fit a cubic: gnuplot> f(x) = a+(b*x)+(c*x*x) gnuplot> fit f(x) 'ch1_100.p' u 1:2 via a,b,c ... rms of residuals 6.24453e-006 (for 10 avg)

Hello Kurt. Thanks very much for the feedback describing how things have moved on. You say NanoVNA-saver can increase the number of steps, but can it also reduce the step size? Even 101 points with

The protector is just that, a protector, and even more: it decreases de efficiency of the capacitive touch screen, so the idea is taking it out at once. Do you leave the protective film when you get a

Hi Alan This an old design I did only to comport those believing a crystal should be measured in a 12ohm environment. It has bearings on mesurements with non VNA instruments I have totally dropped the

There are programs for the N2PK type of instrument that use a fixture like this http://www.hamcom.dk/VNWA/Crystal%20Test%20Fixture%20for%20DG8SAQ%20VNWA%20and%20N2PK%20VNA%20.pdf to measure quartz

This seems a relatively economical LPF https://www.analog.com/media/en/technical-documentation/data-sheets/hmc1044.pdf https://www.ebay.com/itm/283610895215

Hi, I need to go out, so don't have time to re-arrange all these equations into the form you want, but hopefully it will get you started. A section of transmission line with a vacuum dielectric causes

Averaging reduces noise with the square of the number of averages From 1 to 10 reduces a factor 3. To 100 should reduce again with factor 3. But it seems a bit less reduction.

> Try at least 100 points

The vertical scale is the abs of the measured s11. Zero to one. Red an green lines The pink line is S11 open phase minus S11 short phase minus pi. What would the offset delay do to the rotation of S11