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Owen Duffys blog owenduffy.net seems to be offline. Message: "content no longer available" it would be a great loss if his site remained closed. regards

Uhhhh ..... that level of accuracy is only true at one Altitude, Temperature, and Relative Humidity! As they say, "Why be approximately correct when you can be precisely wrong?"

Dave (W0LEV), I climbed aircraft carrier masts in the 70's to tune antenna matching boxes and told "bone-headed" acceptance engineers if they touched the balancing biases in the radio room when the

Don't buy a VNA of any sort, sounds good to me, what do you think. This is accurate to .0000000000001%, close enough?? Mike C. Sand Mtn GA

First, re-download the new firmware file, and make sure you get the one with H4 in the name. Then use nanovna-app to load it. The reason to re-download the file is two-fold: 1) to make sure you got

I've tried installing DiSlord firmware version 1.2.40 on my NanoVNA-H4, but it seems to "brick it"? Going back to 1.2.29 works. Ideas as to why 1.2.40 doesn't work?? I've tried uploading it with

Thanks, Jim Lux! This is why I routinely remind others on the groups to which I subscribe and contribute that we, professionals, amateur radio operators, non-professionals, service technicians, or

Thanks. Useful information. DaveD KC0WJN [email protected]> wrote:

I was thinking the GUM (Guide for Uncertainty of Measurements) Uncertainty of Measurement Results from NIST ( https://physics.nist.gov/cuu/Uncertainty/index.html ) physics.nist.gov (

Jim, Do you refer to John Taylor's "An Introduction to Error of Analysis"? That's the text that I used in college, and the photo on the cover is so great that I have a framed poster of it on a wall

Measuring resistance to 4 or 5 digits is challenging with good repeatability. What’s the temperature coefficient of your unknown? What’s the tempco of your measurement system. And of course, the

For anything above 1 GHz (radio astronomy), I use the SMA standards which are rated to 20+ GHz. I have both the N and SMA HP cal kits. Dave -

Probably not 12. :) But really, let’s look at it. Reflection coefficient is what? <0.005 or <0.0025? Rho= (Z1-Z2)/(Z1+Z2) So we’re looking at about 3 or 4 digits, which is pretty good. The

Hi WW6X HP 909 coax terminaison seems to be garanteed to 50 +/- 0.2 Ohm from DC to 2Ghz , and it costs more than twice NanoVNA's . For HF band it should have better accuracy . Some resistor meters

If one were to buy an HP 909C with ISO IEC 17025 Accredited certification (about $400 total), how many guaranteed decimal places would that have? -- ww6x

?Indeed. Well, that’s, what, 1 part in 1E12? There are relatively few things one can measure to that kind of precision. In the Radio Science world, they measure the round trip delay of a radio

The problem with that, of course, from a basic error analysis perspective, is that any other values used in any equation using a value of Z? with 12 (or 14) significant figures will probably have

The impedance of free space is Z? = 376.730313412(59) Ω. I, for one, will not stand for any measurement with less accuracy. -- ww6x

It is close enough for YOU. It is NOT close enough for everyone.

ER calibration allow compensate DUT impedance mismatch in S21 measurements But on H4 not allow fix Port 2 impedance mismatch due to memory limits (need additional space) On LiteVNA and V2 implemented