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In January there was an item on viewing spurs from HTs ect. I ordered two 40 db anttenduators, 1, 10 & 1, 50 watt. They showed up while I was in the hospital with a heart attack. Now I have a battery powered heart and can't find the original item.

I would appreciate anyone's help.

73 de KF7SLM, Jim

Rudi. THANK YOU for that awesome reply!
Much appreciated!!!

ron
N4UE

Hello Jean,
I have documented a practial example for measuring the cable impedance, see:


Is that more understanable for you?
73, Rudi DL5FA

Your response does not address the problem I encountered.

Yes, pictures are worth thousands of words!

Once calibrated, what does the SWR show with nothing connected to either
port - preferably, display the Smith Chart. But if you are not familiar
with that, just read the SWR with nothing connected and let us know. All
but the NANO-F should read SWR on only channel 0. You do not need Ch 01
for SWR measurements.

Dave - W ?LEV

On Fri, Feb 28, 2020 at 7:31 PM Bob Albert via Groups.Io <bob91343=
[email protected]> wrote:

Make sure you are set up for Port 0 reflection.
Bob
On Friday, February 28, 2020, 11:29:35 AM PST, Carl <cwebs@...>
wrote:

Larry, I have the manuals and read through everything I can find on the
interweb. Also Youtube videos. Every time I try to do the SWR readings it
shows SWR 1.00 and a straight line. On the hand held antennas and my HF
antenna. Might be a bad unit but I don't want to give up yet. However there
is a 16 oz. wammer standing by. I did the Cal. and made sure I had the
correct frequencies set. It's hammer time!

--

*Dave - W?LEV*
*Just Let Darwin Work*
*Just Think*

Carl,
It would help if you provided a picture of your screen and test set-up. Sometimes new users aren't used to operating an analyzer with two channels and try to perform SWR measurements on CH1 instead of CH0. If you only want to use the NanoVNA as an antenna analyzer, then turn off all CH1 traces and only connect your antenna to CH0. As Larry posted, This information is covered in the user guides in this group's Wiki page.

- Herb

19
Hi Herb, Peace be upon You and Yours All.
I had to reinstall the software and take my Nanovna - H apart and using a jumper to revoke it.
I tryed bevore without installing the software new, no chance, also zadik could help.
only the hint from Gyula could help.
I will be very careful in the future, but still there is no posibility to save my settings,
that was the reason to update.
Sincerely
** Ari **

Make sure you are set up for Port 0 reflection.
Bob

Larry, I have the manuals and read through everything I can find on the interweb. Also Youtube videos. Every time I try to do the SWR readings it shows SWR 1.00 and a straight line. On the hand held antennas and my HF antenna. Might be a bad unit but I don't want to give up yet. However there is a 16 oz. wammer standing by. I did the Cal. and made sure I had the correct frequencies set. It's hammer time!

Jean, here is how I do it.
1. Set up for Smith chart2. Run a sweep to see how the curve runs around near the edge of the chart3. Narrow the sweep range to a bit more or less than the frequency where the curve goes about 180 degrees4. Move the marker a step at a time to see at what frequency the reactance goes through zero, or crosses the axis, or where it switches from capacitance to inductance5. Divide that frequency in half6. Set the stimulus to that half frequency, CW7. Read the capacitance or inductance8. With a calculator determine the reactance of that capacitance or inductance at the CW (half) frequency9. That reactance is cable impedance.
In step 8 you use the formula for reactance, either 2pi Lf or 1/(2pi C f).? After you do it three or four times it becomes routine.? To nail down the decimal point I start with 1000000 on the calculator and (for capacitance) divide by 2, then by pi, then freq in MHz, then cap in pF.? Readout is Ohms cable impedance.
If the cable is open circuited at the far end, it will be a capacitance reading.? If it's shorted at the far end it will be inductance.? The longer the cable, the lower the frequency.
Bob

Hello all.
Still puzzled by all the stuff we can do with this device that were out of reach beside buying big bucks HP or (bigger bucks) R&S .

I'm running a genuine NanoVna H with the last eddy firmware (7.0) and NanoVNA saver 0.2.2
With regards to TDR measurements, I'm pretty sure I'm missing something obvious, but I can't find a way to have a precise idea of the cable impedance.
I can extrapolate from the scale on the left side, but it is not precise. The markers on the TDR screen are "only" giving me the length of the cable.

Additional question, I'm not sure to understand the physical meaning of the cable impedance after the "end" of the cable.
What is it and will it have an influence on any antenna connected.

Thanks in advance

Jean

Thank you Luc. That is a marvelous presentation. Thank you very much for all that work.

Larry, AE5CZ

Programs to fix windows 10 driver issues are usually a scam.


--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK

This topic was already discussed here a few times and it's written-up in the Forum Wiki.

Win 10 isn't supposed to need a separate driver for the nano.
Why not just provide the website here?

After using Nanovna-saver for awhile, it fails to find the virtual com port.

I have the solution ? well, not me, but I found someone who does. They
have a program that fixes the driver on Win10.

Email me for the link to their website ?

Robert

Read the User Guides, Carl.
There are several on the forum.
To perform a complete reset, with no calibration, you need to connect the device to a PC and use TeraTerm or another comm program to talk to the Nano's command console.
the 'clearconfig 1234' command will reset the unit - but - read the manual(s) first.

More info, I only want to use this unit as an antenna analyzer at this time, Carl

I got my Nanovna-H a week ago and after many tries I can't get it to display SWR trace. I now have it so messed up I need to restore it to factory default. So I seem to be dumb and need help. Can anyone tell me how to set it up for doing SWR readings and I might need step by step guidance. Next, how do I restore to factory new settings. Thanks for any help to get me on track, Carl

Sounds like a static discharge may have done something.
The schematic is available so why not do some simple troubleshooting?
Make sure the 3.3v regulator is working: 5V in and 3.3V out.
Disconnect the battery and see if the unit runs OK off of a USB only power - does the charge LED light?

I have had my nanoVNA since September. Have loaded several different versions of FW without issue.

Today, after doing a calibrate, it locked up. Unresponsive to touchscreen. NanoVNA-saver can't talk to it. Power-cycling and pulling the battery have no affect.

Options, besides trash can ?

Thanks,
Steve