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More Smith chart tricks:



Brian

Hi Dave

as asked here below the attached new measurements with renormalized Z0 coax 78.5 Ohm and 50 Ohm ( first balun Zc= 62 Ohm) , cursor at the same frequency 14.125Mhz .

73's Nizar .

Hi Dave

Thanks
I do not use any external artifact to take S21 Losses measurements with equivalent 78.5 Ohm coax Z0 , i just use the DiSlord Z0 renormalisation option on Display menu, this option take on consideration all computing's needed to acte as a real 78.5 Ohm NanoVNA .

For measuring characteristic impedance of my Balun i use My owne purely experimental methode , no computing nor modeling just measuring the resistor value that focused the Smith diagram on one dote (resistor trimmer termination) and read the renormalized impedance value that make it exactly on the center of the the shart, it's easy methode, reliable and accurate enougth without any computing errors and estimation, only direct experimental measurement , see screenshoot illustration.

73's Nizar

According to the Github page it is the latest "Official" release, Feb 24 2025 . I just d/l it last week.
Don't know about older units. I have a Deepelec V3 and seems to be fine

Instead of reading where the plot intersects, read the numbers at the top
of the screen which is where your cursor is placed. You have:

-0.774 dB loss at 54.6 + j 35.2 ohms equivalent of 64 ohms for the
total impedance
-0 440 dB loss at 80.7 + j 24.8 ohms equivalent of 84 ohms for the
total impedance

The total impedance is derived by calculating the SQRT of the SUM of the
SQUARES.

Note that using the reflection measurement option as illustrated in the
first image, the total loss is 0.5 of the measured value as the RF must
pass twice through the network. The ratios above don't change.

So the loss at nominally 54 ohms real is 0.167 dB greater at 81 ohms real.

Also note that due to the non 50-ohm or non 72-ohm Zo of the transmission
line transformer (common mode choke), the Zo of the choke will transform
either resistance to something else between 50 and 80-ohms.

What you are using for your 50 and 72 ohm non-reactive loads for the load
in your common mode choke - the disc in the first picture?

How did you measure the impedance of our common mode choke? I usually take
two measurements to determine this:

1) Measure the capacitance with the far end of the choke open terminated.
This will give you the capacitance of the windings (pretty close).

2) Measure the inductance with the far end of the choke short terminated.
this will give you the inductance of the windings (pretty close).

Measure both of these using the Smith Chart and the cursor.

Then calculate the characteristic impedance of the transmission line choke
(common mode choke) using the following:

Zo = SQRT [Measured Inductance in Henries / Measured Capacitance in Farads]

NOTE: 1 ?H = 1E-6 H and 1 pF = 1E-12 F

Dave - W?LEV



both the

On Sun, May 11, 2025 at 6:03?PM Team-SIM SIM-Mode via groups.io <sim31_team=
[email protected]> wrote:

Hi All

i tryed to change the balun designe with the same FT140-43 but with 1X12
turns this time , I measure the charateristic impedance of the balun is
around 142 Ohm ( see Smith shart focused on the graph center) , but this
time with 78.5 Ohm renormalized coax impedance it gives the half with 50
Ohm normal coax , huge diffrence around 1db at 30Mhz , in add this new
balun seems have much more losses -2.5 db compared to the first one
-0.2db , why ?? what is not correct with this second balun , see
illustration below .
73's Nizar .

--

*Dave - W?LEV*


--
Dave - W?LEV

Hi All

i tryed to change the balun designe with the same FT140-43 but with 1X12 turns this time , I measure the charateristic impedance of the balun is around 142 Ohm ( see Smith shart focused on the graph center) , but this time with 78.5 Ohm renormalized coax impedance it gives the half with 50 Ohm normal coax , huge diffrence around 1db at 30Mhz , in add this new balun seems have much more losses -2.5 db compared to the first one -0.2db , why ?? what is not correct with this second balun , see illustration below .
73's Nizar .

Hi Dave
Thanks
Pse take a look to the graphic curve , the losses difference is huge over all the band from 50Khz to 30Mhz , marker value not so important here .
73's Nizar

Please compare at the same frequency. Your 50-ohm (actually 52-ohm)
measurement is at 27.7 MHz. Your 72-ohm measurement is at 14.2 MHz.
Please repeat at the same frequency and get back with us.

Dave - W?LEV

On Sun, May 11, 2025 at 4:47?PM Team-SIM SIM-Mode via groups.io <sim31_team=
[email protected]> wrote:

Hi

I am a little confused, my 1/1 balun done with FT140-43 2x10 turns with
1mm wire as illustrated by photo attached, i want to measure losses by S21
Logmag function after a good thru calibration, with renormalizing the coax
Zc impedance from 50 Ohm to 78.5 Ohm it gives me the double of losses with
78.5 Ohm coax compared to 50 Ohm coax Z, i can not explaine this ? why ?
see S21 responses attached , knowing that i measured the caracteristic
impedance of the balun it is around 62 Ohm as showen by graphic attached
here , any help ?

H4 + 1.2.40
73's Nizar

--

*Dave - W?LEV*


--
Dave - W?LEV

Hi

I am a little confused, my 1/1 balun done with FT140-43 2x10 turns with 1mm wire as illustrated by photo attached, i want to measure losses by S21 Logmag function after a good thru calibration, with renormalizing the coax Zc impedance from 50 Ohm to 78.5 Ohm it gives me the double of losses with 78.5 Ohm coax compared to 50 Ohm coax Z, i can not explaine this ? why ? see S21 responses attached , knowing that i measured the caracteristic impedance of the balun it is around 62 Ohm as showen by graphic attached here , any help ?

H4 + 1.2.40
73's Nizar

Hi
here my best adjustement to the balun around FT140_43, Zc = 62 Ohm , (SWR=1.25:1 with 78 ohm coaxial cable) .
the impedance is centered to the Smith shart and focused there with a resistance trimer for all HF band from 50kHz to 30Mhz..

73's Nizar

Is nanovna saver version V0.7.3 the latest?

Is it backward compatible to all (older) nanovna hardware/firmware and all the various forms of the nanovna implementations?

Understand that some features will not function on older units without updating their firmware.
However, only interested in the most basic of operations including electrical delay which was standard
way back in 2019.

When Rune was developing the program, it was available as an application executable (exe) and nothing else was required to install.
Is that still the case?

Thank you,

Hi

It helps me to adjust gaps between 1/1 current balun wires to have a Zc = 48.5 Ohm (initially wires are colled together gives 39 Ohm characteristic impedance of twean lead of balun ) .

amazing tools, Now i should adjust another curren balun for my 78 ohm coax .

73's Nizar

Hi

It will be very appréciated if we can save display smoothing setting to the C0 , C1... C6 calibration memory.

If we can display batterie voltage with a very small police characters below batterie graphics

73s Nizar

Hi
Graphic image option of H4+DiSlord firmware 1.2.40 done by the Nano_App 1.1.218 is a really amasing option, it make bigger the Nano VNA screen with larger PC screen and mouse option running superbely . Thanks to DiSlord .
some bugy behaviors still there with windows windowing , Hope it will be debuged soon to make it more reliable , I like it a lot , it make easier almost things graphically. especially less confusing between 0 and 8 characters .

73's Nizar

I don't plan on putting one up. I do not see it as the best antenna to use.
People say they have worked a lot of stations with it, but others have said
they worked people using a gutter or bedspring as an antenna. :-)

The best 40m antenna I have built and used was a vertical magnetic loop
antenna, 58 feet long for the horizontal run, 12 feet high vertically. I
had the bottom wire 5 feet off the ground. It was a two-turn loop with a
quarter wavelength of 70 ohm cable at the feedpoint, which made the
impedance at the other end of the 70 ohm cable 50 ohms. Low radiation angle
made it an outstanding DX antenna on 40m. I ran the design on MININEC and
it predicted a gain of 5.5 dB over a dipole off the sides. Of all the 40m
antennas I've used, it was second only to a 40 meter beam.

Zack W9SZ

On Thu, May 8, 2025 at 1:38?PM Mike N2MS via groups.io <mstangelo=
[email protected]> wrote:

The impedance of an EFHW is dependent on many factors such as
surroundings, groung and wire gauge and changes at the higher harmonic
frequencies. Has anyone actually measured the antenna?

Mike N2MS

On 05/08/2025 2:19 AM EDT Mike via groups.io < mail@...

wrote:


I tested my unun by placing a 2400 ohm resistor in series with the S21
input. This loads the secondary with approximately 2450 ohms which is the
typical source resistance for an EFHW


--
Mike G8GYW

<>
Virus-free.www.avg.com
<>
<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

The impedance of an EFHW is dependent on many factors such as surroundings, groung and wire gauge and changes at the higher harmonic frequencies. Has anyone actually measured the antenna?

Mike N2MS

Hey Jon,

Yes mate, despite the age, if aren't learning something new every day, then there's something wrong .
Always great to step outside of the circle once in a while Jon.

Have an awesome day.


Pete

I have also learned a good bit from this discussion Pete.

73
Jon, VU2JO

On Thu, May 8, 2025 at 3:41?PM VK4CCV via groups.io <Fritzables=
[email protected]> wrote:

Jon & Mike,

Thanks very much with this.
I have learnt so much over the past 24 Hours and still a long way to.

Cheers


Pete

On Wed, May 7, 2025 at 11:19 PM, Mike wrote:

I tested my unun by placing a 2400 ohm resistor in series with the S21 input.
This loads the secondary with approximately 2450 ohms which is the typical
source resistance for an EFHW

Mike, you can use this program to measure your transformer without using a resistor. It lets you vary the effective resistance by typing instead of soldering.



Brian

Jon & Mike,

Thanks very much with this.
I have learnt so much over the past 24 Hours and still a long way to.

Cheers


Pete