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For some reason I’m having trouble downloading your updated files.

Charles Miller

On Jul 14, 2021, at 12:04 PM, Barry K3EUI <k3euibarry@...> wrote:

?This is the most recent video on my presentation:
Nano VNA Part I The Basics (not much math)
Nano VNA Part II The Under the Hood Approach (Advanced topics)

I'll also include the latest PDF of the slides - enough for a few hours
of discussion

The video listed below was recorded a few days ago by the Leicester Radio
Society (UK)
TU G8PGO David Carter.

I'm learning as I am playing, so here are the latest two videos
The Part I is just the "basics" without any of the math. That video was
also recorded.
If you spot any errors on either video please let me know. This is rather
technical stuff.
The ending on both presentations was a bit abrupt since I ran out of time.


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have fun watching
de k3eui Barry
k3euibarry@...

HELLO ALL

As of July 16th:

I gave the Nano VNA talk in two installments to the Leicester Radio
Society (UK) but I did not record it and I did not post it. I'll contact
the person who did post it and see what happened to it.

I only reference this (recorded) video as the latest talk I have given on
the Nano VNA

Part I was the basic stuff - very low math but I do mention Smith Chart
I treat the nano VNA as just another tool in your ham radio toolkit
I show how you can use the Nano VNA to check out coax, filters, and
antennas.
All of the graphs were produced by NANO VNA SAVER software (free,
Win 10).
THANK YOU to the author of that app.

Part II Uner the Hood - looks at all of the measurements and calculated
parameters in more detail.
You can Calibrate the Nano VNA via software (Nano VNA SAVER) and do a
lot more with the tool.
I then go into gory detail about the Smith Chart - but not assuming
one is already familiar with it.
Part II ends with looking at resistance, reactance, and impedance and
how these plot on Smith Charts.
How do antenna tuners "cancel" the reactance on your feedline by
introducig a CONJUGATE match?
There is a bit of magic and fancy math, but I try to avoid that.
Warning: there is a Smith Chart quiz in the talk and in the PDF.

Conclusion: antennas do not "need to be resonant" to work well
(i.e. 43 ft vertical) but the entire antenna system (including feed line)
needs to present a reasonable load to your rig. The typical SWR meter gives
you a reading (2:1) but gives no information as to what you can do to
improve your antenna.

Thus, the Nano VNA is a much better "tool" at analyzing your antenna than
a mere SWR meter.

This is the best I've been able to do and explain (as a non-engineer)
after one year experience with VNA.

If I can get it posted again, feel free to share both the video and the
extended PDF with others.

This has been and continues to be a learning challenge for me.
There are many ways to "see" a concept. I'm looking for a 9th grade level
right now.
I hope my video Zoom and the PDF is aiming at the right audience.

73
K3EUI Barry
Philadelphia
K3euibarry@...