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When I (try to) move a marker on the Nano screen (not PC) the jog wheel switch causes problems. It is too sensitive and starts to change frequency settings.

In calibration for measurement and in measurement at RF frequencies, high-Z
is far more difficult than a short or proper 50-ohm termination. Take 144
MHz and assume you are attempting to measure 1 kohm. There will always be
present roughly 0.5 to 1 pf in the measurement. At 144 MHz, 0.5 pF =
-j2210 ohms. This is over twice the real part even at 0.5 pF - a very
small capacitor.

True, the output impedance (if you will, resistance plus a small amount of
several pF of capacitance) of an HF tube amplifier is very high, between
1000 and 4000 ohms (+/-). The pi-L network between the tube plates and the
output to the antenna feedline matches that high-Z (and renders pure
resistance) to 50-ohms. That impedance is not measured with a VNA but
rather but by using standard Ohm's Law based calculations specifically
tailored for determining the values of the matching network to enable
maximum power transfer.

450 ohm ladder line is a real differential transmission line as is 300-ohm
TV twin lead as are long parallel close-spaced ribbons of copper strip as
are parallel copper traces on opposing layers of a PC board. I use
parallel open wire transmission line between my home brew L-network
matching network (a.k.a., "antenna tuner" - it does NOT 'tune' the
antenna!!) and the feed point of my 450-foot long doublet. Works great as
a relatively lossless transmission line and withstands high SWR with
insignificant additional loss.

Dave - W?LEV

--

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

I'll tell you what I have done to test high impedance RF.

I built myself a fixture PCB, you can see if here:



One of the parts of the fixture PCB is a ZIF socket connected to two SMA
female connectors. It is very useful for measuring leaded components.

I calibrated the VNA (the one I designed and built) using the ZIF socket
lever up for open circuit, a very short wire between two holes for short
circuit, and a 1/4 watt 51 ohm resistor for load. The leads were trimmed
to minimize the inductance of the resistor.

At 1-30 MHz, I then could measure the impedance of a 10k ohm resistor. The
results were accurate over the entire frequency range, between about 9800
to 10200 ohms.

At 1-600 MHz, I could measure the impedance of a 1k ohm resistor. The
results were between about 950 and 1050 ohms over the entire range up to
about 550 MHz, where the resistance dipped slightly to about 900 ohms.

Because I only use the SI5351A up to 200 MHz (as that's all its speced
for), 600 MHz is the maximum frequency I can test with the third harmonic.
Fifth harmonic and up tends to be useful mainly just for crude antenna
measurements.

I'm a happy camper. Got the Hugen firmware flashed, ordered a 100 count pack of diodes from Amazon via next day Prime delivery and as of last night, I soldered one of those bad boys on and I now have a working battery gauge. Great little device! I've got one of the 3D printed enclosures around mine as well.

My tube amplifier takes exception to your statement:

"High Z is hard to obtain at RF. "

The amp wants to know who do you think has been talking on 40 meters for
the last 30 years?


And the 450 ohm ladder line does not agree with your concepts of
transmission line either.

But I told them that I would talk to you on their behalf. So please be more
open to all the work they do, OK ? :)
All done now, I hope they settle back down. (-:

Nels
NE7LS

Got the cable today, did NOT work. This is number two. This cable is
an OTG data cable USB-C (nanovna) ti Micro-USB (samsung android phone)

NanoVNA Web App from play store says "no device found" when press connect.

What the ^%$ to do now?

Shouldnt any OTG data cable work???

Any advice appreciated!

On Sun, Feb 16, 2020 at 4:06 PM Kayak via Groups.Io
<kayak1176@...> wrote:

Since my phone has a MicroUSB,. I just ordered this one. If it works, then
I may try to find a way to update the wiki (?) so others can have one to go
to directly.


USB C to Micro USB OTG Cable, CableCreation 0.65 ft Type C Braided Cord,
480Mbps Compatible with MacBook (Pro), Galaxy S8, S9, S10, Pixel 3 XL, 2
XL, Android Devices, 0.2M/ Space Gray


On Sun, Feb 16, 2020, 1:27 PM gary <w9td@...> wrote:

Yes, but I used this one


As it also can power the attached device (NanoVNA)

High Z is hard to obtain at RF. For parallel twin lead with #16 wire, the spacing is 0.3 inches for 300 Ohms. The spacing for 1000 Ohms is 105 inches!

for 144MHz in HP8753C column you have a typo I think...

--
Regards,

Slawek/SP9BSL

Sorry your table is all over the place can work out which is which.

Go higher than 1-2K ohms, think you will start to see the difference.

A few weeks ago I decided to measure S11 of a few metox wire ended
resistors and got the following results at 10 MHz.

Nominal value Rp
50 50.5
100 99.85
180 181.7
270 267.9
390 386
470 466
1000 986

I was pleasantly surprised by my results.

Phil G3SES

Best results are to terminate both channels with a good 50-ohm load.
However, this afternoon, I went through the full cal for other purposes and
got -90 dB on return loss measurement to about 50 MHz once the cal was
complete (NANOVNA-F).

Dave - W?LEV

--

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

is correct if you only have one 50 ohm load ..
If, on the other hand, you have two 50 Ohm loads, it is right to load both ch0 and ch1 with a 50 Ohm load.

--
*73, Lucio I0LYL Rome, Italy*

Hi all am i correct in thinking that when i get to do the isolation cal,i put a 50 ohm load on ch1 and leave ch0 open?,just to clarifie,cheers all in advance.73

Dave, next time, just try using courier fixed font for any tables. I find that usually works well.?



On Sun, 16 Feb 2020 at 5:37 PM, David Eckhardt<davearea51a@...> wrote: Let's just try a PDF attachment.? See attachment.

Dave - W ?LEV

On Sun, Feb 16, 2020 at 10:32 PM David Eckhardt <davearea51a@...>
wrote:

If the group.io messes with the formatting (which it likely
did....grrrrrrrr.....grrrrrr), can I attach an MS Word document???

Dave - W?LEV

On Sun, Feb 16, 2020 at 10:29 PM David Eckhardt via Groups.Io <davearea51a=
[email protected]> wrote:

OK.....I just had to do it.? NANOVNA-F measured data compared to the HP
8753C measured data.? Subjects are:

? ? ? 1)? 220-ohm 1/8-watt? 10 %
? ? ? 2)? 470-ohm 1/8-watt 5 %

Both VNA's were calibrated SOL.? Measurements were made by placing the
cursor at the designated frequencies and reading the complex impedance from
the Smith Chart (HP) and Saver (NANOVNA - F).? I cut the resistor leads as
short as possible and inserted them into their respective female connectors
(NANOVNA-F: SMA Port 01.........HP 8753C:? BNC at end of 50-ohm cable where
cal. standards were placed).? In both cases, the reflection measurement
method was utilized.? Measured data follows:

? *Frequency (MHz) *? ? ? ? ? ? ? ? ? ? *220-ohm*
? ? ? *470-ohm*
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? *NANOVNA-F *? ? ? ? ? *HP 8753C*
? ? *NANOVNA-F*? ? ? ? *HP 8753C*

? ? ? ? 49.5? ? ? ? ? ? ? 197.3 - j15.9? ? ? ? ? 209 - j19.7
? ? 456.1 - j20.5? ? ? ? 464.8 - j17.1
? ? ? ? 144.0? ? ? ? ? ? ? 206.9 - j20.6? ? ? ? ? 109 -
j19.7? ? ? ? ? ? ? 451.4 - j58.2? ? ? ? 466.9 - j17.8
? ? ? ? 299.6? ? ? ? ? ? ? 198.1 - j18.7? ? ? ? ? 193 -
j9? ? ? ? ? ? ? ? ? 415.3 - j105.1? ? ? 429.2 - j17.2
? ? ? ? 403.9? ? ? ? ? ? ? 186.9 - j17.1? ? ? ? ? 190 -
j6.7? ? ? ? ? ? ? ? 405.2 - j108.5? ? ? 406.3 - j115.6
? ? ? ? 700.0? ? ? ? ? ? ? 182.2 - j17.2? ? ? ? ? 188.5 -
j8.9? ? ? ? ? ? 320.1 - j174.0? ? ? 413.1 - j178.3
? ? ? ? 955.0? ? ? ? ? ? ? 180.2 - j18.0? ? ? ? ? 181.2 -
j2.2? ? ? ? ? ? 265.2 - j192.7? ? ? 273.9 - j153.4

Draw your own conclusions.

My Own Conclusions:? PRETTY DARN GOOD....NO.....EXCELLENT.....comparing
$60 to $25,000++ (in its day).

? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? I do not own a Rig Expert but have
used a couple.? I'll take the NANO's any day over far more $$$ for "the
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? others".

? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? And, these are portable.? The HP
8753C is anything but portable!!!!

Dave - W?LEV

--

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

--

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

Let's just try a PDF attachment. See attachment.

Dave - W ?LEV

On Sun, Feb 16, 2020 at 10:32 PM David Eckhardt <davearea51a@...>
wrote:

If the group.io messes with the formatting (which it likely
did....grrrrrrrr.....grrrrrr), can I attach an MS Word document???

Dave - W?LEV

On Sun, Feb 16, 2020 at 10:29 PM David Eckhardt via Groups.Io <davearea51a=
[email protected]> wrote:

OK.....I just had to do it. NANOVNA-F measured data compared to the HP
8753C measured data. Subjects are:

1) 220-ohm 1/8-watt 10 %
2) 470-ohm 1/8-watt 5 %

Both VNA's were calibrated SOL. Measurements were made by placing the
cursor at the designated frequencies and reading the complex impedance from
the Smith Chart (HP) and Saver (NANOVNA - F). I cut the resistor leads as
short as possible and inserted them into their respective female connectors
(NANOVNA-F: SMA Port 01.........HP 8753C: BNC at end of 50-ohm cable where
cal. standards were placed). In both cases, the reflection measurement
method was utilized. Measured data follows:

*Frequency (MHz) * *220-ohm*
*470-ohm*
*NANOVNA-F * *HP 8753C*
*NANOVNA-F* *HP 8753C*

49.5 197.3 - j15.9 209 - j19.7
456.1 - j20.5 464.8 - j17.1
144.0 206.9 - j20.6 109 -
j19.7 451.4 - j58.2 466.9 - j17.8
299.6 198.1 - j18.7 193 -
j9 415.3 - j105.1 429.2 - j17.2
403.9 186.9 - j17.1 190 -
j6.7 405.2 - j108.5 406.3 - j115.6
700.0 182.2 - j17.2 188.5 -
j8.9 320.1 - j174.0 413.1 - j178.3
955.0 180.2 - j18.0 181.2 -
j2.2 265.2 - j192.7 273.9 - j153.4

Draw your own conclusions.

My Own Conclusions: PRETTY DARN GOOD....NO.....EXCELLENT.....comparing
$60 to $25,000++ (in its day).

I do not own a Rig Expert but have
used a couple. I'll take the NANO's any day over far more $$$ for "the
others".

And, these are portable. The HP
8753C is anything but portable!!!!

Dave - W?LEV

--

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

--

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

If the group.io messes with the formatting (which it likely
did....grrrrrrrr.....grrrrrr), can I attach an MS Word document???

Dave - W?LEV

On Sun, Feb 16, 2020 at 10:29 PM David Eckhardt via Groups.Io <davearea51a=
[email protected]> wrote:

OK.....I just had to do it. NANOVNA-F measured data compared to the HP
8753C measured data. Subjects are:

1) 220-ohm 1/8-watt 10 %
2) 470-ohm 1/8-watt 5 %

Both VNA's were calibrated SOL. Measurements were made by placing the
cursor at the designated frequencies and reading the complex impedance from
the Smith Chart (HP) and Saver (NANOVNA - F). I cut the resistor leads as
short as possible and inserted them into their respective female connectors
(NANOVNA-F: SMA Port 01.........HP 8753C: BNC at end of 50-ohm cable where
cal. standards were placed). In both cases, the reflection measurement
method was utilized. Measured data follows:

*Frequency (MHz) * *220-ohm*
*470-ohm*
*NANOVNA-F * *HP 8753C*
*NANOVNA-F* *HP 8753C*

49.5 197.3 - j15.9 209 - j19.7
456.1 - j20.5 464.8 - j17.1
144.0 206.9 - j20.6 109 - j19.7
451.4 - j58.2 466.9 - j17.8
299.6 198.1 - j18.7 193 -
j9 415.3 - j105.1 429.2 - j17.2
403.9 186.9 - j17.1 190 -
j6.7 405.2 - j108.5 406.3 - j115.6
700.0 182.2 - j17.2 188.5 - j8.9
320.1 - j174.0 413.1 - j178.3
955.0 180.2 - j18.0 181.2 - j2.2
265.2 - j192.7 273.9 - j153.4

Draw your own conclusions.

My Own Conclusions: PRETTY DARN GOOD....NO.....EXCELLENT.....comparing
$60 to $25,000++ (in its day).

I do not own a Rig Expert but have
used a couple. I'll take the NANO's any day over far more $$$ for "the
others".

And, these are portable. The HP 8753C
is anything but portable!!!!

Dave - W?LEV

--

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

OK.....I just had to do it. NANOVNA-F measured data compared to the HP
8753C measured data. Subjects are:

1) 220-ohm 1/8-watt 10 %
2) 470-ohm 1/8-watt 5 %

Both VNA's were calibrated SOL. Measurements were made by placing the
cursor at the designated frequencies and reading the complex impedance from
the Smith Chart (HP) and Saver (NANOVNA - F). I cut the resistor leads as
short as possible and inserted them into their respective female connectors
(NANOVNA-F: SMA Port 01.........HP 8753C: BNC at end of 50-ohm cable where
cal. standards were placed). In both cases, the reflection measurement
method was utilized. Measured data follows:

*Frequency (MHz) * *220-ohm*
*470-ohm*
*NANOVNA-F * *HP 8753C*
*NANOVNA-F* *HP 8753C*

49.5 197.3 - j15.9 209 - j19.7
456.1 - j20.5 464.8 - j17.1
144.0 206.9 - j20.6 109 - j19.7
451.4 - j58.2 466.9 - j17.8
299.6 198.1 - j18.7 193 -
j9 415.3 - j105.1 429.2 - j17.2
403.9 186.9 - j17.1 190 - j6.7
405.2 - j108.5 406.3 - j115.6
700.0 182.2 - j17.2 188.5 - j8.9
320.1 - j174.0 413.1 - j178.3
955.0 180.2 - j18.0 181.2 - j2.2
265.2 - j192.7 273.9 - j153.4

Draw your own conclusions.

My Own Conclusions: PRETTY DARN GOOD....NO.....EXCELLENT.....comparing $60
to $25,000++ (in its day).

I do not own a Rig Expert but have used
a couple. I'll take the NANO's any day over far more $$$ for "the
others".

And, these are portable. The HP 8753C
is anything but portable!!!!

Dave - W?LEV

I removed the comma from the end of the message link below. It works now.?



On Sun, 16 Feb 2020 at 4:39 PM, hwalker<herbwalker2476@...> wrote: ? I agree with Kurt that the NanoVNA's inaccuracies above 300 ohms are not that bad.? I had the same frustrations with an HP Agilent 8753C Network Analyzer with 85046A S-Parameter Test Set. Once you get very far from 50 ohms its accuracy also suffers.? An HP applications engineer I contacted explained that's pretty much the nature of the beast for any low impedance 50 ohm VNA, and there's no reason to expect any more of the NanoVNA.? As Kurt said, the test fixture also plays an important part in measurement accuracy, especially above 1 MHz.? Flying leads test fixtures basically only work for quick checks in the kHz region.

? Erik wrote a Matlab script, /g/nanovna-users/message/7685?to?use an external bridge to calibrate the NanoVNA at other than 50 ohms, but I never saw any feedback from users who tried using it at 300, 1000, or higher impedances.? There were actually about 34 messages in the "Using an external RF bridge with NanoVNA " topic and I don't remember a definitive test procedure write-up coming out of it.

- Herb

I agree with Kurt that the NanoVNA's inaccuracies above 300 ohms are not that bad. I had the same frustrations with an HP Agilent 8753C Network Analyzer with 85046A S-Parameter Test Set. Once you get very far from 50 ohms its accuracy also suffers. An HP applications engineer I contacted explained that's pretty much the nature of the beast for any low impedance 50 ohm VNA, and there's no reason to expect any more of the NanoVNA. As Kurt said, the test fixture also plays an important part in measurement accuracy, especially above 1 MHz. Flying leads test fixtures basically only work for quick checks in the kHz region.

Erik wrote a Matlab script, /g/nanovna-users/message/7685, to use an external bridge to calibrate the NanoVNA at other than 50 ohms, but I never saw any feedback from users who tried using it at 300, 1000, or higher impedances. There were actually about 34 messages in the "Using an external RF bridge with NanoVNA " topic and I don't remember a definitive test procedure write-up coming out of it.

- Herb

Since my phone has a MicroUSB,. I just ordered this one. If it works, then
I may try to find a way to update the wiki (?) so others can have one to go
to directly.


USB C to Micro USB OTG Cable, CableCreation 0.65 ft Type C Braided Cord,
480Mbps Compatible with MacBook (Pro), Galaxy S8, S9, S10, Pixel 3 XL, 2
XL, Android Devices, 0.2M/ Space Gray