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Hi Larry,
there's no reason not to use it - other than not knowing what it actually
returned :-) I see Herb has now answered that question ;-)

--
Rune / 5Q5R

On Tue, Jan 28, 2020 at 07:48 AM, <nanovnauser@...> wrote:

has anyone written a decent manual for the nanosaver s/w?
=======================================================

Probably the best write up has been by Gunthard Kraus at

There is a lot of other information available in the groups Wiki. You might try your hand at producing a manual and contributing back to the group if you produce something decent.

- Herb

Hi all,ive a antenna consisting of 2 80m mobile whips in a dipole configuration as i dont have room for anything else,i get different readings on both my analysers,the antenna is at the end of a 60ft run of coax,is it better to cal the vna by putting the cal load and short etc at the end of the cable run,ie where the coax joins the antenna?,thanks in advance.73

has anyone written a decent manual for the nanosaver s/w?

this is what i used for a case,3.2 inch screen too.,just waiting for a 90 degree usb c adaptor to arrive.

Bravo

On Tue, Jan 28, 2020 at 07:04 AM, Larry Rothman wrote:

What does the info console command return?
If it says H4 somewhere, why not use that?
================================================
The info command returns the following:

Kernel: 4.0.0
Compiler: GCC 8.3.1 20190703 (release) [gcc-8-branch revision 273027]
Architecture: ARMv7E-M
Core Variant: Cortex-M4F
Port Info: Advanced kernel mode
Platform: STM32F303xC Analog & DSP
Board: NanoVNA-H 4
Build time: Jan 18 2020 - 22:54:30

Its a lot of information to parse but I guess sudo code like < If in info_cmd 'STM32F303xC' > or < If in info_cmd 'NanoVNA-H 4' > would work.

As far as actual capture coding goes, the following, pulled from your NanoVNA-saver capture module, works for me:

ser.flushInput() # Clear the buffer
cmd = "capture" + "\r" # Add return to command string
ser.write(cmd.encode())
ser.flush() # Send out now

try:
timeout = ser.timeout
ser.timeout = 2
ser.readline() # trash echoed command
image_data = ser.read(320 * 480 * 2)
ser.timeout = timeout
rgb_data = struct.unpack(">153600H", image_data)
rgb_array = np.array(rgb_data, dtype=np.uint32)
rgba_array = (0xFF000000 +
((rgb_array & 0xF800) >> 8) +
((rgb_array & 0x07E0) << 5) +
((rgb_array & 0x001F) << 19))
# ((rgb_array & 0x001F) << 3))
image = Image.frombuffer('RGBA', (480, 320), rgba_array, 'raw', 'RGBA', 0, 1)
image.show()
image.save(str(sys.argv[1])+'.png')
print("\nCaptured screenshot")
ser.close()
print('\n closed: {}'.format(port))
except serial.SerialException as exc:
print("Exception while capturing screenshot: %s", exc)


When I used your original ((rgb_array & 0x001F) << 3)) the H4 captured screen colors were incorrect. Changing it to ((rgb_array & 0x001F) << 19)) produced correct captured screen colors on my set-up.

If you need a beta tester I'd be glad to help.

- Herb

I have adapted a $5 case (don't forget your 20% off coupon) from Harbor Freight for carrying the nanovna. The removable storage bins provide good places for connectors etc.

--
Dave, WB5NHL
5BDXCC, 311 countries confirmed
@dkjellqu

I followed the advice to remove the drivers from USBdeview and voila !
My NanoVNA now shows up with COM11 (COM7 before) and the communication works as predicted.

Now, what other devices are not working anymore ? :-)

Thanks for the help
Patrick TK5EP

heyI have one of those cases in the garage
great idea!

Hello,

Thought you might get a kick out of this:

I bought a microphone and got a hard plastic, foam-lined case with it.? Makes

a good home for the Nano.

In the kit:

two RG316 cables

Calibration standards

sma male to N female cable

sma male to SO239 cable

sma female to male N adapter

N female to PL259 adapter

sma female to female adapter

sma male to male adapter

73

Glen K4KV

I'm getting exactly the same results after trying the same configurations and tests....
I don't have another USB5 cable to try..

Will try on another computer.

I have a NanoVNA-H sw version0.4.0-3 build on nov 25

The DFU

I installed USBDeview as per Gyula, and it shows ChibiOS/RTVirtualCOM port driver is active
and loaded for COM3 (which is the correct COM port).

Correct COM port, but the wrong driver.
Delete that and hope that Microsoft's USB Serial Device driver gets
loaded subsequently:
C:\WINDOWS\system32\DRIVERS\usbser.sy

What does the info console command return?
If it says H4 somewhere, why not use that?

Hi Rune -

Can any of you help me with this?

I just hacked my Perl script to handle this by brute force, namely:
keep reading into a buffer until len(buffer) does not increase,
then use that accumulated buffer length to sort screen size.

Hi, dear friends!
Made modifications of my NanoVNA-H rev.3.3 today.
Resistors values were changed according to rev.3.4 schematic.
Also added some capacitors.
A trick. The resistors were soldered upside down. )))
The first screenshot is with calibration loads on CH0 and CH1 before modifications.
The others, LOAD, OPEN and SHORT after mods.
Firmware used is ver.0.4.5-4 by hugen79.

Shorted end is generally better then open end. Open end has some stray field leakage which is equivalent to a couple tenths of pF depending on cable type. Doesn't matter much at VHF and below freqs but does create some error at UHF freqs. Short has some inductance but can be made pretty low resulting in less error then an open end.

For velocity factor better to use shorted end half wavelength coax and look for low resistance real impedance frequency. You can do multiple half wavelengths but cable loss will raise the minimum impedance measured. Imagine a very long coax with greater then 30 dB attenuation. The impedance measurement will read the Zo of cable regardless of load Z put on other end of cable because of cable loss.

So what about open calibration, above about 500 MHz the calibration could start to compute a correction for open end stray capacitance. The open end calibration connector actually adds a little more stray capacitance but it does protect against outside stray interference signals. For nano's this is probably swamped by accuracy of bridge with chip components and PCB stray capacitance. There are also a lot of poor 50 ohm calibration loads supplied with nano's. The worse I have seen contained a leaded metal film resistor. If 50 ohm load has a long case, suspect it. A good SMA 50 ohm load will cost about $15 from a reputable source. Shorts are usually pretty good, other then poor plating allowing oxidation/corrosion over time.

Hi Lajos

Just read this document. It contain all the answers. Copy the link text and paste it into a browser URL line.
The link will probably not survive ? I have tested it and it works.

to calibrate the VNWA using C and L polynomial coefficients in addition to delay.pdf

Kind regards

Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af pgc1682@...
Sendt: 27. januar 2020 22:43
Til: [email protected]
Emne: Re: [nanovna-users] Calibration settings for NanoVNA-saver using SDR-Kits BNC calibration kit



Hi Kurt,



I will borrow high quality OSLT N standard. I will try on Nanovna and WVNA. I not fully understand values conversion to WVNA arbitrary settings.



This calibrator 50 ohm load not have inductance or capacitance modell. Which is the settings line for this load in WVNA?



Sort, and open have offset loss parameters and C0-C3, L0-L3 C0-C3, L0-L3 values already converted from your manual, but how to convert to wvna offset loss? Offset loss availabe dB/sqrt(GHz) or Mohm/s format. All L0-L3 parameters zero, what is the simple formula?



Not understand S= Z= Y= values in WVNA, (selectable for in arbitrary open/short/load), this labels S, Y, Z not same all calibrator files supplied with WVNA.



73, Lajos

Gyula and Oristo

I installed USBDeview as per Gyula, and it shows ChibiOS/RTVirtualCOM port driver is active and loaded for COM3 (which is the correct COM port). I then tried PuTTY using the information from Oristo's post. PuTTY just opens up to a black screen with a green cursor in the top left hand corner. When I press enter, I get no response or prompt. Any other thoughts?

HP Journal - 1984-11, "An Advanced 5-Hz-to-200-MHz Network Analyzer"



It's interesting to be able to compare block diagram and description of the inner workings of one of HP's Network Analyzers to the current series of inexpensive VNAs that all use a similar method of mixers, frequency generators and compute engines (CPUs).

Technology has sure come a long way.

Enjoy!

...Larry