开云体育

That 200 Ohms is not the same as a 200 Ohm resistor at any frequency other that 1 MHz. Again Impedance, not resistance.? Kent

Thanks, but I must disagree: the nanoVNA provides a resistance output as well as a reactance, and that is what I was reading to be 200 ohms at 1 MHz...

Not really resistance, but impdeance. Got a good old DC Volt Ohm Meter? Try that, but you see only 1 or 2 Ohms. Most of the Digital VOM;s are using pulses that are much like RF.So they are reading as

This thread inspires me to ask a question that is not directly about my nanoVNA: I have a toroid from a flea market that is blue, has OD = 0.875”, ID = 0.51”, and length = 0.3125”. I wrapped 6

You don't need anything other than the NANOVNAs to measure inductance as a function of frequency. Invoke the Smith Chart, and use the cursors to measure the L at any frequency within your sweep.

On Sat, 16 Oct 2021 Cliff <mailto:kd4gt.tn@...?subject=Re:%20%22Q%22%2C%20Coils%2C%20toroids%2C%20and%20guesswork%3F> wrote about an on line toroid calculator available at:

Some may find this does-it-all calculator useful also. It is my go to site for all things toroid. …. and even obvious and easy to remember and get to. Just type the following in the address bar of

I would find it interesting to see curves of L(uh) at different B field amplitudes. Such as with a weak antenna signal vs an amplifier output. I learned in my first AC circuits class that AsubL drops

I contacted the author of the program (Miguel Vaca) by email and sent him my suggestions and bug report. He has just released a new version which plots L versus frequency. Those designing toroid

Everything helps.. Thanks!

Jim, I agree with you. Here are some measurements of a 20M dipole. First measurement was made using calibrated range of 1 to 30 MHz. Next was using same calibration but "zooming in" to 13

Barring pathological cases

When you choose a set of frequency limits, and a set of frequencies in that span (number of frequency steps), then only and exactly that set of frequencies is calibrated. If you then make a

Roger, Note that I am only clever enough to post a link to the calculator. The Aussie, Jose Miguel Vaca, VK3CPU is the one who did all the magic so I don't need to use the CF scale on my slip stick.

Cliff, That is a very impressive calculator!. A suggestion - You only calculate L with the initial permeability. You already plot X so it would be nice if you could add L to the graph since it varies

Please read ANY of the user guides and learn what the letters on the left side of the display mean. On Sun., 17 Oct. 2021 at 10:18 a.m., Joe WB9SBD<nss@...> wrote: Now when you save a calibration

YES.

Hello Andy, I just installed the drivers from the ST site on a Win10 computer using the "Absolute Beginner's Guide to NanoVNA" yesterday in hopes of connecting to a NanoVNA-H4. The guide is very

Now when you save a calibration to a memory. Is that good still after a power down and then fired up again some other day? Joe

I had wondered about this. I will calibrate over several different ranges (e.g. 143 to 147 MHz, 431 to 433 MHz, etc.) and save each one. I am assuming the calibration is saved each time one of the