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I built an antenna tuner that has a Raspberry Pi controlling a stepper motor (roller inductor) and two servos (two capacitors). I created a function for it that will step through all possible

Before you do any new cal., be sure to clear any past cal memories. Dave - W?LEV wrote: -- *Dave - W?LEV* *Just Let Darwin Work*

I have calibrated the VNA. With the short plug it shows 1:12.76 SWR. After calibration if I reinsert the short plug it shows SWR of 1:9554.1 to 1:2147483647.47. Is there away to do a hard reset

The second program is TLW (Transmission Line for Windows) by Dean Straw (N6BV) one of the editors of the ARRL Antenna Book. It is a good complement to TLD because it can plot what is happening along

There has been a lot of discussion about transmission lines recently. I thought the group might be interested in some very useful free tools. The first one is TLD - Transmission Line Details by

I redid my simulation assuming that Torbj?rn Toreson did not use a current balun at the feedpoint. An additional antenna element that represented the outside surface of the coax shield was added.

What.s woo-doo electronics?

That's a very curious result that I didn't see coming. Well worth figuring out. Here's a python script to demonstrate what Roger says. I chose L and C at random to be 1uH and 200pF. Though I still

And such are used as "all pass" networks to get phase shifts between two arms.

That is correct. You need to write the admittance for each series branch and isolate out the real and imaginary parts. For that case the value for the resonate point is 1/root(LC), BUT modified by the

If the components were ideal components there would be no resonant frequency. The "equivalent parallel reactance" of C and L would be equal and opposite at all frequencies and the impedance would be

Can someone please shed some light on the definition of resonance in conjunction with an antenna. I'll make an attempt. Let's agree that "resonance occurs when +/- jX is zero". It does not take

At least using 2019 nanoVNA firmware, order DOES matter: the device is making the "next" measurement until that expected button is pressed. If an unexpected button is pressed, current device data is

Anne, I think your central point is that with a 50+j0 ohm load and a 50 ohm transmission line, the transmitter sees a 50 ohm impedance looking into the coax regardless of the length of the coax.

This is a very lame post. Your behaviour is the reason devs like 1of11 are not fully sharing their work. I suggest you to have some respect. A ter?a, 8/09/2020, 14:22, <gary.sewell@...>

Can someone please shed some light on the definition of resonance in conjunction with an antenna. Let's agree that "resonance occurs when +/- jX is zero". It does not take knowledge of x-degree

Correction: Inductive impedance is positive, capacitive impedance is negative. So scanning through a quartz crystal from high frequencies to low, the impedance is positive, then negative between

On Tue, Sep 8, 2020 at 06:41 AM, Dr. David Kirkby, Kirkby Microwave Ltd wrote: > > This will be difficult to draw in an email, so I will describe it, too > > ——— R

Thanks. I just noticed site was back up.

Regarding a quartz crystal, another puzzle is the characteristic impedance over frequency. If you check the impedance on your nanovna you will see that it is inductive at frequencies above series