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Here is a screen capture of my 40 m coaxial cable trap. Obviously the center freq is too high but it is work in progress. Roughly one can see that the 3db bandwidth is around 130kHz, Q around 62. Next

Hi, Calibration at the far cable end can be difficult at times, as not always you have easy access to your antenna feedpoint. An alternative way to get what you want, using easily measured rig side

And here is another introduction. Read section 2.1.3 This document from 1990 also mentions the ratio of cross ratios and describes various different approaches to calibration next to the well known

Attached document should give some answers The impedance model of the calibration load represents the actual impedance of the load either as it is calculated from theoretical modelling or from

Interesting..... My question still doesn't seem to be getting through... Yet it remains a simple one. :-) Let me try this again. Question: What justifies characterizing the calibration standards?

You would need to have in the ballpark of 80 nH of series inductance due to series parasitics.. Seems a little high but not out of the question. Measure caps a low freq first to get values with

Also, they choose lower frequencies not only because it's easier to measure at low frequencies, but also because many components suck at higher frequencies, and by specifying low test frequencies,

Hi wb2uaq, Yes - i define resonance as R+j0. I had read that if there are no common-mode currents on the feedline then length of coax shouldn't matter as far as swr/resonance is concerned. If it does

On Tue, Jan 7, 2020 at 03:43 PM, Brian wrote: " ..A 100pF silver mica then gives the attached which indicates 105pF at 7MHz, 109pF at 14MHz and 126pF at 28MHz .."

What is your definition of resonance in this situation? If you measure say R + j0 at the antenna, the Z you measure at the input end will be dependent on the electrical length of the transmission

I have often thought that there should be a law that all portable devices have a hard off switch or battery disconnect. Both issues can be fixed by the clever tinkerer. For the NVNA, add a battery

On Tue, Jan 7, 2020 at 02:44 PM, Ron Bussiere wrote: " I made a simple tool to install the board side connectors, but also doubt they will survive very long. .."

Hi Brian, Unfortunate but a 100 pF will NOT remain a 100 pF C independent of frequency. And in fact the C value will increase with an increase in frequency. In your case with the values you provided,

Brian, How much different are your results if you clip to the capacitor 0.25" away from the cap body vs 0.5" away from the cap body? The inductance of the leads in series with the capacitor will form

On the nanoVNA(H) the spec on the IP5303 says its standby is less than 100 uA, assuming it's 'Smart load detector' detects the unit has been turned off and puts the chip in standby. For a 450 mAH

For flying wires and alligator clips to work, everything must be in the *exact same position* as when the calibration was done. I use a couple of BNC female connectors mounted on a piece of double

Hi Gary, Great questions. I have no idea what the answers are. But Erik’s and John’s replies seem reasonable. Perhaps Dr. Kirby might know. Best regards, Jeff

I have also been looking to answer how accurate should the NanoVNA be at HF. Most components I want to measure are wire ended so my test jig is a 60cm RG316 with SMA on each end cut in half. Each cut

Hi Herb. I made a simple tool to install the board side connectors, but also doubt they will survive very long. My first thought was to solder them onto the board, but that would probably cause the

Interesting, I'd never seen that parameter on data sheets before. That'll give me something new to study ;-) 73 de Andy