Re: Building Pi Network with VNA given values
All four are all 2 element ell networks. If the values have been
calculated correctly each one would provide the required match. (1) has
low-pass characteristics. (4) is a high-pass network. The
By
David McQuate
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#39760
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Building Pi Network with VNA given values
Hi All.
I need to build a Pi Network for my circuit as shown in the fig below.
1741926237187.png
So I have a 'Pi Matching Network' in my circuit. The datasheet asked me to build a Pi Matching
By
shlomo537678@...
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#39759
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Re: Am I in the right track ?
Do you have a trace inside the board to be the other half of the transmission line?
One turn through the ferrite is not enough. The impedance goes up approximately as the square of the turns.
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Roger Need
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#39758
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Re: Am I in the right track ?
Hi everyone,
No, I haven't abandoned yet ! I got my revised pcb (attached picture) yesterday
1- Revised ground plane dimensions which I made the same as the test board shown in the antenna
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Nico
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#39757
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Re: Help with LPF Measurement
Very good Mitch.
Happy to see you suceeded in beating the electrons into submission.
Lesson learned... Neatness counts.
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alan victor
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#39756
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Re: Help with LPF Measurement
yay indeed.. Pretty cool.
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Jim Lux
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#39755
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Re: Help with LPF Measurement
THAT looks much better built .. and shows the predicted results ... GOTCHA :-)
looks neat .. and works like it should
so you see its very often not just the components you use but how you arrange
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Siegfried Jackstien
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#39754
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Re: Help with LPF Measurement
Jim, Dave, et al.,
Thank you very much for your suggestions. I rebuilt the filter using discarded SMA connectors I found in my junk box along with actual 270 pF caps that I ordered overnight from
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Mitch NK3H
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#39753
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Re: Help with LPF Measurement
This - get some 4 leg SMA jacks and solder two of the legs to the copper clad at the edge of the board. Cut the upper two legs off. That will give you a nice transition.
Depending on where you are,
By
Jim Lux
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#39752
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Readings are not correct for NanoVNA F V2.
Does anyone have a web-site or youtube that goes through the set-up on using the F V2 for checking Coax lengths. The new one I have does not show the correct length, example a known 15.24m / 50ft coax
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CLIFTON HEAD
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#39751
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Re: Help with LPF Measurement
How do you know it's filtering the harmonics out? Feeding in a square wave (into a non-resistive load) might not have the harmonic structure you expect.
It's really hard to interpret the wiggles after
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Jim Lux
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#39750
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Re: S-Parameter Plotter
Larry,
I still use Brian's excellent antenna simulation programs today. In fact, just about every week. (Different story not for here.)
But, I run them on both a very new macOS computer and a
By
The Greene Family
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#39748
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.NanoVNA-H v3.5_L: white screen - how do I connect USB to fix?
I couldn't connect to the unit and somehow managed to wipe the processor.
I've tried resetting it to reconnect, but the only response I get is in
STM32Cube Programmer 'UR is set by HWrst' or something
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Taracait
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#39747
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Re: Help with LPF Measurement
Things are beginning to look a bit more like a LPF with the "ground"
connected! Other suggestions have been made which are right on. Keep us
posted on your progress.
Dave -
By
W0LEV
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#39746
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Re: Help with LPF Measurement
You may be looking for the graphical version of the map, but I threw this into the AI Grok app on my iPhone and it listed them all out.
“ Menu Structure Map for the NanoVNA F V2.”
You may or may
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JimReed
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#39745
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Re: Help with LPF Measurement
There are a bunch of them online. Have you tried Googling?
Compare the menu that you think is right to your NanoVNA because there are
several variations.
[email protected]> wrote:
By
William French - AA1BF
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#39744
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Re: Help with LPF Measurement
Off subject, does anyone know where to get a Menu Structure Map for the NanoVNA F V2. My new one did not come with one. Thanks
________________________________
Sent: Thursday, March 13, 2025 1:54
By
CLIFTON HEAD
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#39743
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Re: Help with LPF Measurement
Mitch,
Try making the ground connection to your filter very short, say 5mm or so. Also, try multiple ground wires. The currents to ground from all the capacitors in the filter flow through that
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John Gord
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#39742
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Re: Help with LPF Measurement
Hi Jim,
Thank you for your suggestions. I will shorten leads and properly dress the components tomorrow. BTW I had no 270 caps but had 50s and 220s, hence the two caps in parallel.
You make a
By
Mitch NK3H
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#39741
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Re: Help with LPF Measurement
Hi Jim,
Correct. I failed to connect them. I've repaired it and get a slight improvement. See pic just posted. Many thanks. Best, Mitch NK3H
By
Mitch NK3H
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#39740
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