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Can you do a calibration and a measurement of a 25 ohm resistor
after you have fixed the output power to 6mA, so in console mode
power 2
and then the calibration and measurement
and see if this gives any difference in the 25 ohm measurement.

First capture is with 50 Ohm calibration at power 2;
second is then with 50+50 tee and 2dB/div:

There are so many out there it is hard to make a decision.

Only a few individuals here have experience with more than one nanoVNA,
with most acquired from vendors who may ship different versions at different times.
According to @gabuchan, there are 3 main sources for nanoVNA;
most here credit Hugen as the key designer of assembled devices,
but Hugen continually refines his design and reportedly sells mostly in China.
It seems likely that many devices on Amazon or elsewhere are by resellers of Hugen's devices.
Hugen confirmed that one acquired from NooElec was indeed one of his, but not the latest.
If USB-C direct attachment is important,
then a device with nanovna.com label on the back is a necessary,
but not sufficient (since easily copied) factor.


Meanwhile...

* NooElec is indeed the US supplier designated by edy555,
who created the original nanoVNA kit and maintains the primary firmware repository.

* Greg W4GAP's linked version IMO is almost certainly a genuine NooElec-blessed-by-edy555 NanoVNA,
probably by Hugen but, lacking the nanovan.com label on the back, may not be the most current design.

* The one linked by hwalker appears genuine, but vendor Leiyini does not appear to specialize in electronics
and IMO may be more likely to source items from multiple suppliers.

* Images for the item linked by hamrad88 are of a so-called "worse clone",
such as I acquired in July and has been satisfactory for my purposes
but less than ideal above 240MHz or so.

* For someone looking for a recent Hugen version >>only from Amazon<<,
the AURSINC version is advertised as "UPGRADED", so returnable if not...

Oristo,

Can you do a calibration and a measurement of a 25 ohm resistor after you have fixed the output power to 6mA, so
in console mode
power 2
and then the calibration and measurement
and see if this gives any difference in the 25 ohm measurement.
I checked hugen's code and once set the drive strength (power) will remain till the unit resets
If no differences then I retract my comment on non-linearities.

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

Hi neb,

The program has been tried by others and works well with Windows XP.
Thanks to neb for writing the program.

Ordered this one today..tnx for the recommendation. There are so many out there it is hard to make a decision. Your advice is based on something other than " a good deal". Now I need to learn how to use it.
Jim K2TL

The 4 save locations versus 5 also seems to be an acceptable trade-off for
larger font size

I always want at least 5 calibrations and do not recall using more than 3 traces at a time.

depreciated and no longer useful

SCANRAW is for applications to grab e.g. more than 101 points, optionally with averaging, while paused.

Can someone that has installed 0.4.0-3 do a S11 measurement of a 25 ohm
resistor from 1 to 900MHz?

Using

Setting 2dB/div

Can someone that has installed 0.4.0-3 do a S11 measurement of a 25 ohm
resistor from 1 to 900MHz?

Using

On Mon, Nov 25, 2019 at 04:41 AM, Larry Rothman wrote:

Si5351 default 8mA output;

During the "Chasing ghosts" series it was discovered that 8mA creates non-linearities.
Can someone that has installed 0.4.0-3 do a S11 measurement of a 25 ohm resistor from 1 to 900MHz?

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

QRP and Oristo wrote:
"it has larger font, so it cannot show full frequency and measured value result and cut-off part of the value"

"4 calibration SAVE areas instead of 5. On the other hand, Hugen maintains code inline that is neither in edy555 nor QRP firmware, so presumably more responsive.
Other space was cleared in previous release (4.0) by
eliminating shell commands: DUMP, SCANRAW, COLOR"

===========================================================

QRP / Oristo, thanks for the responses.

I assume the frequency and measured values are only truncated on the screen and are still transferred at full value when connected to a computer. That trade-off will work for people who desire the larger font size and for most of their work only need a couple of digits of precision on the display.

The 4 save locations versus 5 also seems to be an acceptable trade-off for larger font size.

DUMP and SCANRAW commands, I believe, were primarily used during the developmental and debugging of the original NanoVNA and are depreciated and no longer useful. The COLOR command might be missed by those users that have problems with the default screen colors.

It looks like future firmware developments are going to require more give and take to address the dwindling flash memory space available.

- Herb

Hi Herb -

If the AA version now has 4 traces then,
other than a larger font size,
what differs it from the "ch" version?

4 calibration SAVE areas instead of 5.
On the other hand, Hugen maintains code inline
that is neither in edy555 nor QRP firmware,
so presumably more responsive.

Other space was cleared in previous release (4.0) by
eliminating shell commands: DUMP, SCANRAW, COLOR
.. but I guess those may be also eliminated in Hugen's non-AA version

On Mon, Nov 25, 2019 at 03:29 PM, hwalker wrote:

If the AA version now has 4 traces then, other than a larger font size, what
differs it from the "ch" version?

it has larger font, so it cannot show full frequency and measured value result and cut-off part of the value

On Mon, Nov 25, 2019 at 04:41 AM, Larry Rothman wrote:

" …. Note large font on 4 traces now."
=================================================

If the AA version now has 4 traces then, other than a larger font size, what differs it from the "ch" version?

- Herb

Why not just but a RaspberryPi Zero-W for $10US from Adafruit
and use it as a USB Host to WiFi bridge?

1) power and integration, given the goal of a BLE VNA sensor
2) toggling Pi Wi-Fi off/on between VNA scans could be problematic;
as would leaving it on.
3) "(BLE support is still in the works, software-wise)"

Everyone keeps talking about (relatively) expensive solutions to get? a wireless connection from the NanoVNA.
Why not just but a RaspberryPi Zero-W for $10US from Adafruit and use it as a USB Host to WiFi bridge?


In fact, with some programming, you could remotely command it to scan and store data locally on its SD card.
So - let's get programming.....

...Larry

On Monday, November 25, 2019, 7:27:08 a.m. GMT-5, Oristo <ormpoa@...> wrote:

> ...PCB version of NanoVNA-H to V3.4...easy to DIY Bluetooth connection

The recently announced (for ~ US$20) Arduino NANO 33 BLE claims USB host support:


Based on Nordic nRF52480 (which cannot natively implement USB host),
this may be a minimal hardware prototype for Bluetooth LE via USB with existing nanoVNAs,
except that dedicating the Arduino NANO 33 BLE USB port to host may be too disruptive,
so perhaps prototyping by a USB host shield may still be more expedient:


Cheap USB Host Shields are typically DuinoFun clones, e.g.

Hi Rune,

Again, I would like it very much when "uncalibrated" or? the description of the active calibration-file is shown in the MAIN window, to avoid confusion while working.

Jos


Op 25-11-2019 om 09:26 schreef Rune Broberg:

Hugen's updates from today's NanoVNA-H firmware release:

1.The absolute value of the linear format is displayed;??

2.Si5351 default 8mA output;??

3.The AA version shows 4 traces.??


Note large font on 4 traces now.

...PCB version of NanoVNA-H to V3.4...easy to DIY Bluetooth connection

The recently announced (for ~ US$20) Arduino NANO 33 BLE claims USB host support:


Based on Nordic nRF52480 (which cannot natively implement USB host),
this may be a minimal hardware prototype for Bluetooth LE via USB with existing nanoVNAs,
except that dedicating the Arduino NANO 33 BLE USB port to host may be too disruptive,
so perhaps prototyping by a USB host shield may still be more expedient:


Cheap USB Host Shields are typically DuinoFun clones, e.g.

Your standards could be significantly improved as follows:

Short: Don't use wires, too much added inductance. instead use braid or a thin piece of sheet copper (with hole) pushed down flush against connector body and soldered all around.

Open: Long center pin makes for added uncertainty of reference plane location. Instead, cut off the center pin flush with the connector body.

Load: Resistors floating off the connector body adds inductance. Instead, trim center pin to short stub (~1 mm), and solder down the resistors laying right against the connector body, preferably turned over with the coated side facing the connector body.

Dana (K8YUM)