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Transmission Line Tools
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
By Roger Need · #17277 ·
Re: Definition of resonance
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.
By Roger Need · #17276 ·
Re: Definition of resonance
What.s woo-doo electronics?
By Ross Kay · #17275 ·
Re: What is the resonate frequency of this?
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
By Jerry Gaffke · #17274 ·
Re: What is the resonate frequency of this?
And such are used as "all pass" networks to get phase shifts between two arms.
By Jim Lux · #17273 ·
Re: What is the resonate frequency of this?
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
By alan victor · #17272 ·
Re: What is the resonate frequency of this?
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
By Roger Need · #17271 ·
Re: Definition of resonance
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
By W0LEV · #17270 ·
Re: Order of calibrating
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
By Oristo · #17269 ·
Re: Definition of resonance
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.
By Jerry Gaffke · #17268 ·
Re: Has OneOfEleven gone again?
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@...>
By CT2FZI · #17267 ·
Re: Definition of resonance
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
By Anne Ranch <anneranch2442@...> · #17266 ·
Re: What is the resonate frequency of this?
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
By Jerry Gaffke · #17265 ·
Re: What is the resonate frequency of this?
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 > > ¡ª¡ª¡ª R
By Roger Need · #17264 ·
Re: Has OneOfEleven gone again?
Thanks. I just noticed site was back up.
By gary.sewell@... · #17263 ·
Re: What is the resonate frequency of this?
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
By Jerry Gaffke · #17262 ·
Re: Has OneOfEleven gone again?
There for me right now. New app build today.
By Brian Morrison · #17261 ·
Re: Setting Stop Frequency to 1500 MHz on NanoVNA-H 3.4 #nanovna-h #edy555_nanovna
DiSlord, After playing more with the interface I now see that you can select into the STOP frequency button to manually set this. Up to this point it was using the current marker location to create a
By river@... · #17260 ·
Re: What is the resonate frequency of this?
Yes, the R's have no effect on resonant frequency. They do lower the Q. More interesting is the model of the quartz crystal resonator, consisting of a series R,Lm,Cm in parallel with a Cp The R,Lm,Cm
By Jerry Gaffke · #17259 ·
Re: Setting Stop Frequency to 1500 MHz on NanoVNA-H 3.4 #nanovna-h #edy555_nanovna
Enter as stop frequency more bigger value?
By DiSlord · #17258 ·