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Hi Jim Lux "L , C & R exhibit some frequency-dependent variation; they do not have a perfectly flat response across frequency. This behavior depends on the dielectric material used, skin effect

Not unexpected Zc is sqrt( (R+jomegaL)/(G+jomegaC)) Mostly determined by L/C, but the R is in there too, and it goes up as frequency goes up, because of skin effect. For HF the dielectric loss (G) is

Interesting , the Zo uses to rise a little when the frequency goes down.

Hi for same RG213 cable (25m length) loaded by a 50.3 Ohm resistor I used the same circle methode centered on smith graph with the renormalized Z0 impedance ( option added by DiSlord) for

Hi Dave DiSlord coax function seems using Zc = 1/(4*fr*C0) , fr= is the first resonance frequency with open terminaison it's around 1.7Mhz measured by NANoVNA. C0 = capacitance value at lower

I wonder how the "short / open" method compares using Zc = SQRT [L / C] ? Of course, that will introduce losses due to theoretical infinite SWR. Dave - W?LEV [email protected]> wrote:

Hi I think that this method of small circles centered with the renormalized impedance at the center of the Smith graph, must bring two advantages compared to that used by the DiSlord method: 1) we

Hi below what i have measured on smith graph with my 25m length of RG213 coax cable with a NanoVNA H4 With Dislord function and no terminaison : it gives Z0=51.7 Ohm , it do not change with

I have this problem even with my recently purchased NanoVNA. Sometimes when I switch on, the screen is blank. If I switch off and switch on once again, usually it becomes OK. The problem recurs again

John, Thank you for your advice; I think that is the reason for the fault. I tried that and operated the unit outside of the case and it seemed to work a little better but the menu still flickered

William, Also check for battery swelling causing pressure on the display. --John Gord

Internally-matched power transistors use the internal bond wires as high-Q inductive elements. In conjunction with MOS capacitors they are used to build matching networks inside the package to bring

William, This might be due to the case pressing on the touchscreen Try loosening the mounting screws or perhaps adding thin washers for spacing. --John Gord

Have an old NanoVNA H with the above FW whose display is intermittent. More specifically, the menu turns off and on or will revert to the main menu. I have tried to do the touch cal and touch test

Hi, Brian, I still have mine with the matching speaker. Mine is an NC-183, not an NC-183D. Like you, I really loved that thing. Even now, the sight of it here brings back good memories. But I

Maynard, I bought a NC-183 to replace my S-38D in the early 1960s. I just loved that big receiver. Brian

Hi, Ed, That's true! I remember hearing the phrase "you can work the world with watt and a wet noodle," but I didn't fully understand what was going on at the time. I did cut an old broadcast

I had guessed the DC block above SRF might be useful even when C was not the LF value. Thanks for the insight on R and L, Alan. Brian

Well.....here's another one for you: SM inductors. Most of the suppliers quote Q at 1 MHz. 1) The RF "resistance" (due to skin effect) should be used instead of the DC resistance. 2) Outside of