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FWIW, A good deal of information concerning Heaviside's contributions to EM field theory (including his vector calculus-based formulation of Maxwell's equations as compared to Maxwell's original differential equation-based formulation) is included in Bruce Hunt's book "The Maxwellians".

DaveD
KC0WJN

Thanks for all the fish.
==============================
All spelling mistakes are the responsibilty of the reader (Rick Renz, STK, ca. 1994)
==============================

They were successful:

Hi Nizar,

I am surprised you are having touchscreen troubles with your Deepelec NanoVNA-F.
Try clearing your calibration data and do another touch screen calibration.
Leon changed the touchscreen cal points in the V1.0.5 FW to make it more responsive as some people were having problems getting a good cal previously.
Hopefully this is your problem.

As for buying a NanoVNA-H4, as I said, I am pretty sure the latest HW version uses a 4" IPS screen, so it should perform as well as the -F in sunlight.
The other plus is if you are into frequency references. Erik, the designer of the TinySA products, has written an alternative FW to turn the -H4 into an extremely sensitive Phase-Frequency comparator, the TinyPFA. The FW only works on the -H4, nothing else. You can swap between PFA and VNA capability simply by loading the appropriate FW.
BTW, the FW "update" process can be a bit overwhelming on the -H4 compared to the beautiful simplicity of the -F.
And last, but not least, between Hugen and DiSlord, the development of all the "bells and whistles" on the -H4 runs rings around the -F.

I love my Deepelec NanoVNA-F, but I am thinking seriously about buying an -H4. At the moment, I am torn between the -H4 (and TinyPFA capability) and the SAA-6 6GHz VNA also manufactured by Hugen and supported by DiSlord FW to get the extended frequency capability.

HTH...Bob VK2ZRE

The only other idea I have is to remove, clean, and re-seat the display
cable. It has VDD pins next to gnd pins - maybe there is a short, or some
FOD.

On Mon, Oct 28, 2024, 3:23 PM Jim Ancona N1ADJ via groups.io <jim=
[email protected]> wrote:

On Sat, Oct 26, 2024 at 11:48 PM, Stan Dye wrote:

It could be U11, or it could be something dragging down the output of U11
(some other failing component presenting a too-high load).

It turns out that my board is version 4.2.1, the scrematic is

If you can manage it, I would unsolder and lift the output leg of U11

and see

if the output of the chip pops back up to 3.3V where it should be.

The regulator is LDO1. I managed to lift pin 5. With no load I measure 3.6
volts. If I put a 33 ohm resistor to ground, the voltage goes to 3.3. So it
looks like the regulator is okay. I measure about 3 ohms from VDD to
ground, which seems too low.

Another observation to make is to see if any of the chips is getting

warm to

the touch - if it is pulling down the 3.3V rail, it may be getting hot.

Not surprisingly, LDO1 gets hot if I leave the power switch on for more
than ten or twenty seconds. I can't feel anything else that's very hot
though. I tried lifting one pin of C47, but the measured resistance didn't
change.

And yes, a VDD of 1.7 is a problem. Maybe the initial 2V+ is enough to

turn

the processor on such that it can respond a bit, then as VDD goes down,

the

processor would likely fail.

I agree.

I'm running out of ideas. I doubt I could remove the smaller capacitors
without breaking them and if one of them was a near-short, I think it would
have burned up. I'm happy to hear suggestions of other things to try.

Thanks,

Jim
N1ADJ

Links I have that still work are:
&
.

But they lead nowhere. The memorial project is a heading in Oliver's WikiPedia page:
.
He is buried in Devon.

In 2014 on a lark, I contributed 10 Pounds to an effort of those in Newcastle seeking to refurbish Heaviside's grave site. They sent a picture. I will grab it of my e-Mail.

On Sat, Oct 26, 2024 at 11:48 PM, Stan Dye wrote:

It could be U11, or it could be something dragging down the output of U11
(some other failing component presenting a too-high load).

It turns out that my board is version 4.2.1, the scrematic is

If you can manage it, I would unsolder and lift the output leg of U11 and see
if the output of the chip pops back up to 3.3V where it should be.

The regulator is LDO1. I managed to lift pin 5. With no load I measure 3.6 volts. If I put a 33 ohm resistor to ground, the voltage goes to 3.3. So it looks like the regulator is okay. I measure about 3 ohms from VDD to ground, which seems too low.

Another observation to make is to see if any of the chips is getting warm to
the touch - if it is pulling down the 3.3V rail, it may be getting hot.

Not surprisingly, LDO1 gets hot if I leave the power switch on for more than ten or twenty seconds. I can't feel anything else that's very hot though. I tried lifting one pin of C47, but the measured resistance didn't change.

And yes, a VDD of 1.7 is a problem. Maybe the initial 2V+ is enough to turn
the processor on such that it can respond a bit, then as VDD goes down, the
processor would likely fail.

I agree.

I'm running out of ideas. I doubt I could remove the smaller capacitors without breaking them and if one of them was a near-short, I think it would have burned up. I'm happy to hear suggestions of other things to try.

Thanks,

Jim
N1ADJ

Hi Bob

I have Deeplec Nano-VNA F 4.3'' V2.3 V3.1 FW 1.0.5 but very disappointed by touchscreen on the menu even with good calibration as shown on youtube video, very erratic and bugy , otherwise all is OK even -80db stable range . sweep points limited to 301 right now.
Wondering if it's a good deal to have an other Nano-VNA H4 V4.3 .
73's Nizar .

Hello Nizar,
Before you buy another NanoVNA, what brand of NanoVNA-F do you have Sysjoint or Deepelec?
Have you upgraded to the latest firmware?
If it is a Sysjoint, they no longer support the NanoVNA-F, but the Deepelec FW has been found to work on the Sysjoint unit OK.
You just need to be careful to flash the correct file from the download. The latest Deepelec FW is V1.0.5.
You should do a complete recalibration including the touchscreen calibration.
I have a Deepelec NanoVNA-F HW V3.1 (3 button) and the touch screen is very reliable.
HTH...Bob VK2ZRE

Hi Stan
Thank you very much for all this nice infos about nano vna H4 v3.1.
I will select a supplyer from amazon.de to have some advices from you and others ..

Thanks again
73's Nizar

Hi Jim,
As Roger points out below, you can use a laptop or tablet to connect to your NanoVNA.
Also, if you have the 3" -H model, you could buy a newer -H4.
I believe the latest version uses an 4" IPS screen which will be much easier to read in general and also the IPS screen will be better in sunlight.
HTH...Bob VK2ZRE

Hi Victor , many thanks for the link.
I have the pdf version of the HP-Agilent seminar "Vector Network Analyzer Basics" , by David Ballo
and more recent version , but the course with video and verbal explanation ,
represents a notable contribution to the understanding of the subject matter of the course itself.
Best regards
Maurizio iZ1MDJ

If you are going to do this, don't do it with single frequencies, do a
full sweep.
Anyway, multiple people did this before and posted on this same list.

On Sun, 27 Oct 2024 at 22:40, Matthew Rapaport via groups.io
<quineatal@...> wrote:

Another experiment. What difference does the NanoVNA CALIBRATE>POWER setting produce in the VNA’s signal level?

The Setup:

VNA S11 calibrated to start/stop of 50 MHz–90 MHz, 401 sweep points. Traces are LOGMAG & Smith.
TinySA Ultra set to start/stop of same values as VNA.
Attach 30db external attenuation to SA and set LEVEL>EXT GAIN to -30db so what you see on the screen is the true current the VNA is sending.
Set VNA to CW mode at 60MHz, leaving CALIBRATE>POWER on AUTO. Then freeze trace 1 (yellow).
Set VNA CW mode at 70MHz, . Activate SA trace 2 (green). Set VNA CALIBRATE>POWER to 2mw. Freeze trace.
Set VNA CW mode at 80MHz, CALIBRATE>POWER to 8mw. Activate SA trace 4 (red). Freeze trace.
Activate 4 SA markers. Set 1, 2, & 3 to trace 1, 2, & 4, respectively. (ignore marker 4).

What happens? The VNA CALIBRATE>POWER>AUTO produces the same signal as CALIBRATE>POWER>2mw. AUTO is the same as the lowest POWER setting. A good design choice for safety’s sake. CALIBRATE>POWER>8mw is higher by almost 10mw than AUTO/2mw. If you look at the marker values at the top of the TinySA screen, you see that they are just as expected within the resolution of the SA.

Notice all the spurs around the highest power (trace 4) setting. In the pictures, the SA’s LNA is OFF. If I turn it ON, both the AUTO and 2mw traces also show spurs though smaller than those produced at 8mw.

Picture 1 of both devices
Picture 2 a close-up of the tinySA I hope clear enough to read the marker values
Picture 3 is just a shot of my best (and most expensive) little attenuator: Pasternack, 30db, 2W.

Another experiment. What difference does the NanoVNA CALIBRATE>POWER setting produce in the VNA’s signal level?

The Setup:

VNA S11 calibrated to start/stop of 50 MHz–90 MHz, 401 sweep points. Traces are LOGMAG & Smith.
TinySA Ultra set to start/stop of same values as VNA.
Attach 30db external attenuation to SA and set LEVEL>EXT GAIN to -30db so what you see on the screen is the true current the VNA is sending.
Set VNA to CW mode at 60MHz, leaving CALIBRATE>POWER on AUTO. Then freeze trace 1 (yellow).
Set VNA CW mode at 70MHz, . Activate SA trace 2 (green). Set VNA CALIBRATE>POWER to 2mw. Freeze trace.
Set VNA CW mode at 80MHz, CALIBRATE>POWER to 8mw. Activate SA trace 4 (red). Freeze trace.
Activate 4 SA markers. Set 1, 2, & 3 to trace 1, 2, & 4, respectively. (ignore marker 4).

What happens? The VNA CALIBRATE>POWER>AUTO produces the same signal as CALIBRATE>POWER>2mw. AUTO is the same as the lowest POWER setting. A good design choice for safety’s sake. CALIBRATE>POWER>8mw is higher by almost 10mw than AUTO/2mw. If you look at the marker values at the top of the TinySA screen, you see that they are just as expected within the resolution of the SA.

Notice all the spurs around the highest power (trace 4) setting. In the pictures, the SA’s LNA is OFF. If I turn it ON, both the AUTO and 2mw traces also show spurs though smaller than those produced at 8mw.

Picture 1 of both devices
Picture 2 a close-up of the tinySA I hope clear enough to read the marker values
Picture 3 is just a shot of my best (and most expensive) little attenuator: Pasternack, 30db, 2W.

On Sun, Oct 27, 2024 at 01:35 AM, Jim Shorney wrote:

I recently purchased one of the little XY-FZ35 5A adjustable electronic load
modules

I have a similar item and have been pleasantly surprised at how closely its readings track with my calibrated 5-1/2 digit DMM.
I use it a lot when I can't justify dragging out my 400W electronic load. It, too, is surprisingly accurate, as is my USB meter:
The amount of good measurement tools available for cheap money these days is a great thing.

73, Don N2VGU

I recently purchased one of the little XY-FZ35 5A adjustable electronic load modules to test some battery banks. They are ideal for testing small batteries.



On Sat, 26 Oct 2024 22:40:38 -0400
"Mike C. via groups.io" <mg@...> wrote:

I'm in the weeds reading this but what I do to verify a "working"
battery is: charge it up and then put a calculated load across it while
monitoring the battery health. i.e. choose a fixed load like 100ma and
see what happens, yeah, you do the math.

--

73

-Jim
NU0C

On Sat, Oct 26, 2024 at 12:29 AM, Team-SIM SIM-Mode wrote:

Did NANO-VNA H4 V4.3 has a reliable touchscreen function as it should or it's
vary bugy ??

NanoVNA-H4 has a reliable touch screen. I have never had a problem with it. And no, there are no common 'bugs' not resolved.
It is a very nice device, with lots of features.

On Sat, Oct 26, 2024 at 04:24 AM, Jim Ancona N1ADJ wrote:

VCC is 4.9 volts, but VDD starts out at about 2 volts when I turn it on and
then drops below 1.7. Is U11 the likely culprit?

It could be U11, or it could be something dragging down the output of U11 (some other failing component presenting a too-high load).
If you can manage it, I would unsolder and lift the output leg of U11 and see if the output of the chip pops back up to 3.3V where it should be.
Another observation to make is to see if any of the chips is getting warm to the touch - if it is pulling down the 3.3V rail, it may be getting hot.
And yes, a VDD of 1.7 is a problem. Maybe the initial 2V+ is enough to turn the processor on such that it can respond a bit, then as VDD goes down, the processor would likely fail.
Good luck troubleshooting.
Stan