开云体育

OK...Easy Path.

1) For one, the NANOVNA can not "read" tuner settings. You will have to
record those yourself.

2) The NANOVNA should be connected to the "rig" side of the tuner with a
SHORT piece of good 50-ohm coax (less than 2-feet long).

3) The antenna, itself, should be connected to the "antenna" side of the
tuner with a SHORT piece of good 50-ohm coax (less than 2-feet long).

NOTE: If you are interested only in 160 throughj 20 meters, the coax
lengths can be up to 3 or 4 feet long.

4) Diagramatic "tutorial" on the Smith Chart to determine resonance:

SEE ATTACHMENT, PLEASE BEFORE PROCEEDING

A) Anything above the "PURE RESISTIVE AXIS" is inductive and NOT RESONANT.

B) Anything below the "PURE RESISTIVE AXIS" is capacitive and NOT RESONANT.

C) Anything ON the "REAL RESISTIVE AXIS" is purely resistive and IS
RESONANT but may not be
at 50-ohms which you desire for a match to your 50-ohm coax.

D) ONLY THE CENTER marked in the center with the circle "50 ± j 0 OHMS" is
purely resistive and
50-ohms. This is where you need to adjust your tuner when connected
to your antenna
through the tuner to the NANOVNA. It will be a different setting of
the tuner and
NANOVNA for each frequency.

Let me know if this isn't clear enough. If you have questions, please
email.

Dave - W?LEV

On Tue, Jan 7, 2025 at 6:32?PM Paul Wolf KY4XJ via groups.io <xyroto=
[email protected]> wrote:

I am thinking to build discrete circuits for a specific non-resonant
antenna to operate on HF bands without a remote tuner. I managed to snag
one of the last MFJ-948F Versa Tuner II left in stock. (But, that's an
indoor tuner. I want the tuning done at the base on a non-resonant
antenna.) On a nice day thinking to bring the new tuner right to the
base, tune it up for a few frequencies within each band. How could a
NanoVNA gather values set on the tuner? Seems so possible to use a few
parts and do this outdoor tuning in advance and for increased power.
Smith charts are used for this matching. But, I don't know how to read
discrete values from the Smith Chart on my NanoVNA. I suppose I could also
open up the tuner, use meters for the measurement and build the same.
Whatever, I am sure that my NanoVNA will confirm whether the tuning is
correctly after an individual network is made. Please lead me down an easy
path? Maybe I just need to buy a book and learn this?

Paul - KY4XJ

--

*Dave - W?LEV*


--
Dave - W?LEV

OK...Easy Path.

1) For one, the NANOVNA can not "read" tuner settings. You will have to
record those yourself.

2) The NANOVNA should be connected to the "rig" side of the tuner with a
SHORT piece of good 50-ohm coax (less than 2-feet long).

3) The antenna, itself, should be connected to the "antenna" side of the
tuner with a SHORT piece of good 50-ohm coax (less than 2-feet long).

NOTE: If you are interested only in 160 throughj 20 meters, the coax
lengths can be up to 3 or 4 feet long.

4) Diagramatic "tutorial" on the Smith Chart to determine resonance:

[image: image.png]
A) Anything above the "PURE RESISTIVE AXIS" is inductive and NOT RESONANT.

B) Anything below the "PURE RESISTIVE AXIS" is capacitive and NOT RESONANT.

C) Anything ON the "REAL RESISTIVE AXIS" is purely resistive and IS
RESONANT but may not be
at 50-ohms which you desire for a match to your 50-ohm coax.

D) ONLY THE CENTER marked in the center with the circle "50 ± j 0 OHMS" is
purely resistive and
50-ohms. This is where you need to adjust your tuner when connected
to your antenna
through the tuner to the NANOVNA. It will be a different setting of
the tuner and
NANOVNA for each frequency.

Let me know if this isn't clear enough. If you have questions, please
email.

Dave - W?LEV





On Tue, Jan 7, 2025 at 6:32?PM Paul Wolf KY4XJ via groups.io <xyroto=
[email protected]> wrote:

I am thinking to build discrete circuits for a specific non-resonant
antenna to operate on HF bands without a remote tuner. I managed to snag
one of the last MFJ-948F Versa Tuner II left in stock. (But, that's an
indoor tuner. I want the tuning done at the base on a non-resonant
antenna.) On a nice day thinking to bring the new tuner right to the
base, tune it up for a few frequencies within each band. How could a
NanoVNA gather values set on the tuner? Seems so possible to use a few
parts and do this outdoor tuning in advance and for increased power.
Smith charts are used for this matching. But, I don't know how to read
discrete values from the Smith Chart on my NanoVNA. I suppose I could also
open up the tuner, use meters for the measurement and build the same.
Whatever, I am sure that my NanoVNA will confirm whether the tuning is
correctly after an individual network is made. Please lead me down an easy
path? Maybe I just need to buy a book and learn this?

Paul - KY4XJ

--

*Dave - W?LEV*


--
Dave - W?LEV

This is an interesting problem - I was doing the same, to characterize an LDG autotuner (what *are* the actual L and C steps).

There's two problems you've identified here:
The first is "what is the behavior of the tuner when it's set correctly" - A VNA will give you S parameters (you might have to make two sets of measurements, swapping the input and output).

From that, you can come up with a set of L and C (as wired in the tuner) in any of a variety of simulation programs, and adjust the values so that the simulated S parameters (or Y parameters or ABCD) match those you measured. The tricky thing is that there are parasitics on all the components, so even if the tuner is a CLC you might need to have some more R or L or C.

I highly recommend ELSIE from tonne software - the free edition works well, and it's got an easy interface. Windows only.


But if you want to do a multiband network, then you've got multiple sets of S parameters (one for each band or frequency) and then you want to "synthesize" a network that has that response.

This is a bit more complex. Typically, what you do is pick a topology, and iterate component values in an optimizer, where the thing to be optimized is the response at the frequencies. There are tools that do this (it's sort of like the optimizer in 4nec2) but I'm not familiar with any off the shelf tools (HFSS or ADS probably can do it).

I usually wind up writing some code in Python or Matlab.

This is an interesting problem - I was doing the same, to characterize an LDG autotuner (what *are* the actual L and C steps).

There's two problems you've identified here:
The first is "what is the behavior of the tuner when it's set correctly" - A VNA will give you S parameters (you might have to make two sets of measurements, swapping the input and output).

From that, you can come up with a set of L and C (as wired in the tuner) in any of a variety of simulation programs, and adjust the values so that the simulated S parameters (or Y parameters or ABCD) match those you measured. The tricky thing is that there are parasitics on all the components, so even if the tuner is a CLC you might need to have some more R or L or C.

I highly recommend ELSIE from tonne software - the free edition works well, and it's got an easy interface. Windows only.


But if you want to do a multiband network, then you've got multiple sets of S parameters (one for each band or frequency) and then you want to "synthesize" a network that has that response.

This is a bit more complex. Typically, what you do is pick a topology, and iterate component values in an optimizer, where the thing to be optimized is the response at the frequencies. There are tools that do this (it's sort of like the optimizer in 4nec2) but I'm not familiar with any off the shelf tools (HFSS or ADS probably can do it).

I usually wind up writing some code in Python or Matlab.

I am thinking to build discrete circuits for a specific non-resonant antenna to operate on HF bands without a remote tuner. I managed to snag one of the last MFJ-948F Versa Tuner II left in stock. (But, that's an indoor tuner. I want the tuning done at the base on a non-resonant antenna.) On a nice day thinking to bring the new tuner right to the base, tune it up for a few frequencies within each band. How could a NanoVNA gather values set on the tuner? Seems so possible to use a few parts and do this outdoor tuning in advance and for increased power. Smith charts are used for this matching. But, I don't know how to read discrete values from the Smith Chart on my NanoVNA. I suppose I could also open up the tuner, use meters for the measurement and build the same. Whatever, I am sure that my NanoVNA will confirm whether the tuning is correctly after an individual network is made. Please lead me down an easy path? Maybe I just need to buy a book and learn this?

Paul - KY4XJ

Thanks! As it turned out, I have a RigExpert AA-600, and it was very easy
to use as a TDR. Much easier than the NanoVNA.

Somewhere I have a real TDR, a TEK 1502. But it's in storage and is so
buried I couldn't find it.

My concern about the site was that the cable and antenna (for an FM radio
station) that I needed to measure is on a tower with many other antennas on
it. Instructions for the AA-600 note that transmitted signals from nearby
antennas could affect the TDR measurements and even possibly damage the
instrument. I suppose this could hold true for the NanoVNA, too. There did
not appear to be any effects of other signals on the TDR measurement when I
made it.

Zack W9SZ

On Tue, Jan 7, 2025 at 8:48?AM Robin Midgett via groups.io <RobinK4IDC=
[email protected]> wrote:

W2AEW has a very helpful video on this subject, as well as many very help
videos regarding the nanoVNA & ham radio in general:



Thanks,
Robin Midgett K4IDC


On Mon, Dec 30, 2024 at 5:58?PM Matthew Rapaport via groups.io <quineatal=
[email protected]> wrote:

Great references, thanks!

W2AEW has a very helpful video on this subject, as well as many very help
videos regarding the nanoVNA & ham radio in general:



Thanks,
Robin Midgett K4IDC


On Mon, Dec 30, 2024 at 5:58?PM Matthew Rapaport via groups.io <quineatal=
[email protected]> wrote:

Great references, thanks!

Hi Stan,

Problem solved, your advice was accurate and effective.
1.2.40 uploaded without any issue using bin file and STM Cube Programmer.
Many thanks.
Best regards,

Georges F6DFZ

Don't worry about the MS vs SI designation. Both are handled by the firmware.
There is a setting in the 'Expert Settings' part of the menu structure to select the MS or SI part.
The firmware files with MS or SI in their names simply have that setting initialized to the stated value.

I see that on initial load of Hugen's release page, for v1.2.27, it only shows one file for the -H4, and it has MS in its name. But if you click the link that says "show all 17 assets", it brings up the rest of the list, which includes the -H4-SI files. These would be the correct ones for you (.bin if you use STMCubeProgrammer, .dfu if you use DFuseDemo or nanovna-app).

I would still recommend, however, getting the DiSlord 1.2.40 build, at the link I previously gave, since it has new features and a few improvements, which apparently Hugen has not yet merged into his release.
Stan KC7XE

Hi Stan, thanks for your answer.
I did get the working 1.2.20, and the not working 1.2.27 from this page :
My NanoVNA-H4 needs a SI file as there is no MS in its designation.
I don't see the MS or SI reference in the link to the 1.2.40 update. Does it matter?
I am a little confused about the different versions.
Best regards,
Georges F6DFZ

Georges,
Are you sure you are trying to load the correct firmware file for the H4?
If you try to load the 'H' file or a 'V2' file, it will give a black screen.
And where did you get the 1.2.27 file? If you are upgrading your H4, you just as well get the most current release from DisLord, which is 1.2.40, which is well tested, with additional features. You can get it at this link:

Be sure to choose the ...H4.v1.2.40.bin file for use with STMCubeProgrammer 2.15.0, or the .dfu file for nanovna-app

Hi,
I have been busy a few hours to try to upgrade firmware of my NanoVNA H4 to 1.2.27.

Tried STMCube progammer 2.9.0, which usually is fine, with the correct 1.2.27 bin file, and get a black screen.
Tried to use STMCube progammer 2.15.0 which is said to work, black screen.
Tried NanoVNA app, after updating the driver to DFU, and 1.2.27 DFU file, black screen.

Fortunately, I was able to get my NanoVNA H4 back in business by using STMCube progammer 2.9.0 and 1.2.14 bin file.
The same day, I upgraded the firmware of my TinySA Ultra with STMCube progammer 2.9.0 without any issue.

This subject has been debated, but if someone has an idea...

Best regards and happy new year.

Georges F6DFZ

Hi Jim,

The issue is not of a "mismatch" as you describe, but, rather of the correct (rated) load the QCX apparatus has to see to work as expected.

If we take your example of a DC power supply, for a given voltage it has a maximum current it can supply (out of damaging or having protections tripped), which in direct current is very elastic, whereas in RF is more narrow as open circuits can change the amplifier behaviour to risking of damaging it, or if the load is too reactive put the operating point of the amplifier in a non stable condition, etc.

So looking for a loading that is appropriate to the QCX as per the designer is a sane approach.

IF the power amplifier down the signal path has enough gain, another solution could be attained using an attenuation pad which would load the QCX better and put enough signal to the amp to work adequately, but for such scheme we would need additional data.

On 02/01/2025 17:33, Ted Chesley via groups.io wrote:

Does anyone have recommendations for testing antennas with built-in
LNA's?

Use a TinySA Ultra to view the spectrum at the LNA output would be a start.


For an antenna receiving both the 1.2 and 1.5 GHz signals you might try:



"K700 Full Band L1 L2 L5 High Precision BeiDou GPS GLONASS Galileo RTK Survey
GNSS Antenna"

Good price, and works well.

Cheers,
David
--
SatSignal Software - Quality software for you
Web:
Email: davidtaylor@...
BlueSky: @gm8arv.bsky.social, Twitter: @gm8arv

Would the right approach be to use Port 0 (the source) on the VNA to drive a broadband probe (non trivial) and use Port 1 to measure the response of the antenna/LNA combination. ?You can calibrate your probe by the three cornered hat approach with 3 (notionally) similar antennas. Or choose a probe that is “known by design” (like a NIST standard gain horn or dipole).

If you’re looking for “survey” accuracies (cm or mm) there’s a lot of angle of arrival differences, although a good choke ring/artichoke antenna will have the phase center move by a mm or so over +/- 60 degree from zenith. ?UNAVCO has data on a lot of antennas on their website.

GNSS Antennas - Knowledge Base ( )
kb.unavco.org ( )
favicon.png ( )

( )

If you check the time-nuts mailing list, there’s a fair amount of info on improvised GNSS antennas with very good multipath rejection. Probably about 10 years ago.

Time-Nuts -- Precise Time and Frequency for Amateurs ( )
leapsecond.com ( )
apple-touch-icon.png ( )

( )

Dunno how to separate the LNA, unless there's a tiny coax connector behind
it somewhere that you can jack into. I've seen some tiny coax connectors
that were apparently there for testing purposes (or connecting external
antennas) on some of my old cell phones.

Would it be useful to look at noise response graphs on an SDR receiver with
AGC disabled and the gain fixed, while sweeping the frequencies of interest?

You'd still be measuring response of both the LNA and the antenna at the
same time, but it might give some idea if the combination has significant
falloff in the frequency ranges you're interested in.


--
--Bryon, NF6M

Hi George, Look up "Bias Tee Power Injectors" on Amazon.Lots of them
at $15 or so with stated bandwidth to 6GHz.

-----------------------------------------From: "George"
To: [email protected]
Cc:
Sent: Thursday January 2 2025 5:11:46AM
Subject: [nanovna-users] Measuring GPS antenna bandwidth

I am building a high accuracy RTK locating system to measure my
property lines and the location of buildings on the property. To
achieve centimeter accuracy, it uses signals from multiple locating
satellite constellations on a range of frequencies between 1164 MHz
and 1610 MHz including those used for American GPS. I have several GPS
antennas, including a couple from high end Trimble survey systems but
am unsure if their frequency response extends far enough beyond GPS
frequencies and how flat the response is.

These antennas have built-in LNA's that utilize 3VDC supplied by
receivers via the coax. The antennas and the LNA's need to be tested
to ensure the system meets the bandwidth requirements. Some of them
can be broken down to access the antenna & LNA separately but I'm
unsure how to inject the necessary LNA DC power without impacting the
nanoVNA measurements.

Does anyone have recommendations for testing antennas with built-in
LNA's?

Regards,
George





Links:
------
[1] /g/nanovna-users/files
[2]
/g/nanovna-users/leave/12583772/4866111/1865567994/xyzzy

Those look really good. The ZABT-2R15G+is on the expensive side but is
available from Mini-Circuits in quantities of one. The TCBT-6G+ and TCBT-14+are
less expensive but are only available from Mini-Circuits in a minimum order
of 10 each. Other models are also a lot more expensive. However, all of
these are available in single quantities from Mouser and all but the
ZABT-2R15G also available from Digi-Key.

Zack W9SZ

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

On Thu, Jan 2, 2025 at 10:43?AM Jim via groups.io <teotwaki=
[email protected]> wrote:

Take a look at a RF/DC bias tee

Take a look at a RF/DC bias tee

You are going to find few GPS antennas that pick up both L1 and L2.The classic patch antenna does not have anywhere near the necessary bandwidth.Most of the antennas that do both really have 2 patch antennas in the design.
I test many antennas on my antenna range that have build in circuits.
First you need a DC Inserter.?? Mini-Circuits makes a nice little Inductor/capacitornetwork that does this. .??? Mount it on a PCB with a Connector to your antenna, anda connector to your test equipment.??? Does you VNA cover both GPS bands of interest?
So connect the GPS antenna to the Inserter, then the Inserter to your VNA.?? Add 3 volts of powerto the Inserter power line.
Connect the VNA to a broad band antenna that covers 1-2 GHz. point it at the GPS antennaand you should get a plot of the response.?

A signal generator and Spectrum Analyzer can also be used.
Good luck with your testing?? Kent WA5VJB