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Re: SWR measurement

 

Hi,
an useful range of low S.W.R. in an antenna larger than the theory claims, indicates losses: it is not a good news!
You made a transformer: check it on the right load and also using the simple procedure I suggest in an other post in this thread.
73s.
Paolo IK8XOO


Re: SWR measurement

 

If only Duct Tape were conductive.........?

Dave - W?LEV

On Tue, Dec 21, 2021 at 12:28 AM Greg Giglio <coffeeguy2@...>
wrote:

Sorry, that wasn¡¯t worded well¡­I meant to say, ¡®high SWR with sharp dips
in SWR at the fundamental frequency and it¡¯s harmonics¡¯.

"Silence is golden. Duct tape is silver."

On Dec 20, 2021, at 19:25, Greg Giglio <coffeeguy2@...> wrote:

?Hey, if it works it works! Just curious, by ¡®the whole range¡¯ do you
mean the entire frequency sweep or just the in-band portions of the sweep?
Typically the SWR curve over the entire sweep of an 80-10 EFHW looks like
icicles, with high SWR and occasional sharp dips in the harmonics of the
fundamental. Otherwise I¡¯d suspect that the NanoVNA wasn¡¯t calibrated or
there¡¯s a problem in the connection, but the end result in radio
performance is what counts.

73 de KN7GIG

"Silence is golden. Duct tape is silver."

On Dec 20, 2021, at 19:14, W0LEV <davearea51a@...> wrote:

?As previously mentioned, low SWR is no indication of a good and
efficient
radiator - an antenna. After all, a good dummy load exhibits stellar
SWR
over quite a wide range, but doesn't radiate too well (hopefully).

In modeling the EFHW - BTW, it's a 1/2-wavelength at only one frequency
-
in 4NEC2, it's not that great of a radiator even at its 1/2-wavelength
frequency.

Dave - W?LEV

On Tue, Dec 21, 2021 at 12:00 AM Bo W4GHV <bobarr@...> wrote:
"Good" for me, might taste awful to you.
Not leaving the EFHW here. It works!



On Mon, Dec 20, 2021 at 5:05 PM Max via groups.io <kg4pid=
[email protected]> wrote:

Low SWR doesn't mean it's a good antenna !
On Monday, December 20, 2021, 03:23:01 PM CST, Bo W4GHV <
bobarr@...> wrote:

Will do. I just did a 80--10 meter sweep of my 80-10 EFHW with 12801
data
points on the PC app. Wow!
The Smith Chart and SWR show why the EFHW is so popular. SWR <= 2:1
over
the whole range!

On Mon, Dec 20, 2021 at 1:25 PM Roger Need via groups.io
<sailtamarack=
[email protected]> wrote:

On Mon, Dec 20, 2021 at 09:50 AM, Bo W4GHV wrote:


I just obtained mine, so forgive my lack of knowledge.
I thought it only had 100 data points? How do you scan a wide range?
But, I just read you can do this if it is connected to a PC using
the
software.

Bo W4GHV since '54
I suggest you read the Absolute Beginners Guide in the Files section
of
this group. Also check out the group Wiki.

Roger



















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













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


Re: SWR measurement

 

Sorry, that wasn¡¯t worded well¡­I meant to say, ¡®high SWR with sharp dips in SWR at the fundamental frequency and it¡¯s harmonics¡¯.

"Silence is golden. Duct tape is silver."

On Dec 20, 2021, at 19:25, Greg Giglio <coffeeguy2@...> wrote:

?Hey, if it works it works! Just curious, by ¡®the whole range¡¯ do you mean the entire frequency sweep or just the in-band portions of the sweep? Typically the SWR curve over the entire sweep of an 80-10 EFHW looks like icicles, with high SWR and occasional sharp dips in the harmonics of the fundamental. Otherwise I¡¯d suspect that the NanoVNA wasn¡¯t calibrated or there¡¯s a problem in the connection, but the end result in radio performance is what counts.

73 de KN7GIG

"Silence is golden. Duct tape is silver."

On Dec 20, 2021, at 19:14, W0LEV <davearea51a@...> wrote:

?As previously mentioned, low SWR is no indication of a good and efficient
radiator - an antenna. After all, a good dummy load exhibits stellar SWR
over quite a wide range, but doesn't radiate too well (hopefully).

In modeling the EFHW - BTW, it's a 1/2-wavelength at only one frequency -
in 4NEC2, it's not that great of a radiator even at its 1/2-wavelength
frequency.

Dave - W?LEV

On Tue, Dec 21, 2021 at 12:00 AM Bo W4GHV <bobarr@...> wrote:
"Good" for me, might taste awful to you.
Not leaving the EFHW here. It works!



On Mon, Dec 20, 2021 at 5:05 PM Max via groups.io <kg4pid=
[email protected]> wrote:

Low SWR doesn't mean it's a good antenna !
On Monday, December 20, 2021, 03:23:01 PM CST, Bo W4GHV <
bobarr@...> wrote:

Will do. I just did a 80--10 meter sweep of my 80-10 EFHW with 12801
data
points on the PC app. Wow!
The Smith Chart and SWR show why the EFHW is so popular. SWR <= 2:1
over
the whole range!

On Mon, Dec 20, 2021 at 1:25 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Mon, Dec 20, 2021 at 09:50 AM, Bo W4GHV wrote:


I just obtained mine, so forgive my lack of knowledge.
I thought it only had 100 data points? How do you scan a wide range?
But, I just read you can do this if it is connected to a PC using the
software.

Bo W4GHV since '54
I suggest you read the Absolute Beginners Guide in the Files section of
this group. Also check out the group Wiki.

Roger



















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









Re: SWR measurement

 

Hey, if it works it works! Just curious, by ¡®the whole range¡¯ do you mean the entire frequency sweep or just the in-band portions of the sweep? Typically the SWR curve over the entire sweep of an 80-10 EFHW looks like icicles, with high SWR and occasional sharp dips in the harmonics of the fundamental. Otherwise I¡¯d suspect that the NanoVNA wasn¡¯t calibrated or there¡¯s a problem in the connection, but the end result in radio performance is what counts.

73 de KN7GIG

"Silence is golden. Duct tape is silver."

On Dec 20, 2021, at 19:14, W0LEV <davearea51a@...> wrote:

?As previously mentioned, low SWR is no indication of a good and efficient
radiator - an antenna. After all, a good dummy load exhibits stellar SWR
over quite a wide range, but doesn't radiate too well (hopefully).

In modeling the EFHW - BTW, it's a 1/2-wavelength at only one frequency -
in 4NEC2, it's not that great of a radiator even at its 1/2-wavelength
frequency.

Dave - W?LEV

On Tue, Dec 21, 2021 at 12:00 AM Bo W4GHV <bobarr@...> wrote:

"Good" for me, might taste awful to you.
Not leaving the EFHW here. It works!



On Mon, Dec 20, 2021 at 5:05 PM Max via groups.io <kg4pid=
[email protected]> wrote:

Low SWR doesn't mean it's a good antenna !
On Monday, December 20, 2021, 03:23:01 PM CST, Bo W4GHV <
bobarr@...> wrote:

Will do. I just did a 80--10 meter sweep of my 80-10 EFHW with 12801
data
points on the PC app. Wow!
The Smith Chart and SWR show why the EFHW is so popular. SWR <= 2:1
over
the whole range!

On Mon, Dec 20, 2021 at 1:25 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Mon, Dec 20, 2021 at 09:50 AM, Bo W4GHV wrote:


I just obtained mine, so forgive my lack of knowledge.
I thought it only had 100 data points? How do you scan a wide range?
But, I just read you can do this if it is connected to a PC using the
software.

Bo W4GHV since '54
I suggest you read the Absolute Beginners Guide in the Files section of
this group. Also check out the group Wiki.

Roger



















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





Re: SWR measurement

 

As previously mentioned, low SWR is no indication of a good and efficient
radiator - an antenna. After all, a good dummy load exhibits stellar SWR
over quite a wide range, but doesn't radiate too well (hopefully).

In modeling the EFHW - BTW, it's a 1/2-wavelength at only one frequency -
in 4NEC2, it's not that great of a radiator even at its 1/2-wavelength
frequency.

Dave - W?LEV

On Tue, Dec 21, 2021 at 12:00 AM Bo W4GHV <bobarr@...> wrote:

"Good" for me, might taste awful to you.
Not leaving the EFHW here. It works!



On Mon, Dec 20, 2021 at 5:05 PM Max via groups.io <kg4pid=
[email protected]> wrote:

Low SWR doesn't mean it's a good antenna !
On Monday, December 20, 2021, 03:23:01 PM CST, Bo W4GHV <
bobarr@...> wrote:

Will do. I just did a 80--10 meter sweep of my 80-10 EFHW with 12801
data
points on the PC app. Wow!
The Smith Chart and SWR show why the EFHW is so popular. SWR <= 2:1
over
the whole range!

On Mon, Dec 20, 2021 at 1:25 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Mon, Dec 20, 2021 at 09:50 AM, Bo W4GHV wrote:


I just obtained mine, so forgive my lack of knowledge.
I thought it only had 100 data points? How do you scan a wide range?
But, I just read you can do this if it is connected to a PC using the
software.

Bo W4GHV since '54
I suggest you read the Absolute Beginners Guide in the Files section of
this group. Also check out the group Wiki.

Roger



















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


Re: Here's a Holiday Present for Users of all the nanoVNA Firmware Updates Developed by DiSlord !! #specifications #firmware #features #improvement

 

Thank you so much for your effort. It has been a godsend for those of us who don't have the time to track everything.


Re: SWR measurement

 

"Good" for me, might taste awful to you.
Not leaving the EFHW here. It works!



On Mon, Dec 20, 2021 at 5:05 PM Max via groups.io <kg4pid=
[email protected]> wrote:

Low SWR doesn't mean it's a good antenna !
On Monday, December 20, 2021, 03:23:01 PM CST, Bo W4GHV <
bobarr@...> wrote:

Will do. I just did a 80--10 meter sweep of my 80-10 EFHW with 12801 data
points on the PC app. Wow!
The Smith Chart and SWR show why the EFHW is so popular. SWR <= 2:1 over
the whole range!

On Mon, Dec 20, 2021 at 1:25 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Mon, Dec 20, 2021 at 09:50 AM, Bo W4GHV wrote:


I just obtained mine, so forgive my lack of knowledge.
I thought it only had 100 data points? How do you scan a wide range?
But, I just read you can do this if it is connected to a PC using the
software.

Bo W4GHV since '54
I suggest you read the Absolute Beginners Guide in the Files section of
this group. Also check out the group Wiki.

Roger
















Re: SWR measurement

 

Low SWR doesn't mean it's a good antenna !

On Monday, December 20, 2021, 03:23:01 PM CST, Bo W4GHV <bobarr@...> wrote:

Will do. I just did a 80--10 meter sweep of my 80-10 EFHW with 12801 data
points on the PC app. Wow!
The Smith Chart and SWR show why the EFHW is so popular.? ? SWR <= 2:1 over
the whole range!

On Mon, Dec 20, 2021 at 1:25 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Mon, Dec 20, 2021 at 09:50 AM, Bo W4GHV wrote:


I just obtained mine, so forgive my lack of knowledge.
I thought it only had 100 data points? How do you scan a wide range?
But, I just read you can do this if it is connected to a PC using the
software.

Bo W4GHV since '54
I suggest you read the Absolute Beginners Guide in the Files section of
this group.? Also check out the group Wiki.

Roger






Re: Frequency accuracy

Earle Wilkinson
 

Can someone please help me. Which of the following is correct
I would figure the one that has a 50 ohm impedance but the pattern looks
wrong. What am I doing wrong.

Earle D Wilkinson
(6Y5EW)

Home page:
Email address: earle.wilkinson@...
Echolink: 6Y5RA

On Mon, Dec 20, 2021, 3:01 PM Mike C. <mg@...> wrote:

Think of it in golfing terms. It's like trying to putt with a 'mashie'.
(personally I prefer a #2 wood to putt)

Mike C.

On 12/20/2021 1:48 PM, Dave Daniel wrote:
Remember, the difference between ¡°accuracy¡± and ¡°precision¡± is important.

Accuracy has to do with the degree to which an instrument can determine
a measured value compared to the actual value, independent of the method of
measurement.

Precision is the degree to which an instrument can display the actual
value.
For precision, think about measuring a length; does the scale read in
10ths of an inch, 100ths of an inch? And how accurate are those markings on
the scale?

DaveD

On Dec 20, 2021, at 13:18, Earle Wilkinson <earle.wilkinson@...>
wrote:

?Thanks for the response will let you know the outcome


Earle D Wilkinson
(6Y5EW)

Home page:
Email address: earle.wilkinson@...
Echolink: 6Y5RA

On Mon, Dec 20, 2021, 10:21 AM Jim Lux <jim@...> wrote:

On 12/20/21 12:27 AM, Earle Wilkinson wrote:
Earle D Wilkinson
(6Y5EW)

Home page:
Email address: earle.wilkinson@...
Echolink: 6Y5RA

On Mon, Dec 20, 2021, 3:18 AM Earle Wilkinson <
earle.wilkinson@...

wrote:

New at this.

I got myself an NanoVNA 2 version 4.
Everyone says best thing ever happened.

Better than sliced cheese.

My problem is that I a sticular when it comes to accuracy.

I would like to check my club stations duplexer accuracy on 147.960
high
pass filter with 147.360 as the split on the low pass filter, that is
minus
600 kc split.

Now her is my problem I can only set my markers at 147.300 and
147.900.
Not the exact repeater frequency.

Will the difference of 60 hz make a difference in the accuracy of the
tuning insertion loss etc.

I realise that I need to be accurate at least with the 50 ohms
impedance.
Thanks for your response.
Earle D Wilkinson
(6Y5EW)

Home page:
Email address: earle.wilkinson@...
Echolink: 6Y5RA
Two issues that arise:

#1 The NanoVNA only has a limited number of frequency steps
(101,201,401, depending on which firmware and model) unless you're
using
software on an external computer that does multiple scans. So, if you
set your span to, say, 147 to 148 MHz, then you'll get a measurement
every 10 kHz (with 101 points). Solution here is to use one of the
many
software packages that will talk to the NanoVNA and make multiple scans
and combine them.

#2 The 28 MHz oscillator in the NanoVNA isn't necessarily accurate
enough. I don't recall the spec, but let's say it's on the order of 10
ppm (good for a TCXO) - at 147 MHz, that means it could be off by 1470
Hz.
















Re: NanoVNA v1.1.00 fw pack for all H / H4 / LiteVNA / V2 / V2Plus / V2Plus4 #firmware

 

Thanks DiSlord for the new version, and
Yes, time is 2000/01/01 00:00:30 (LSE) and I can not change it.
Antonio-EA7HJ


Re: SWR measurement

 

Will do. I just did a 80--10 meter sweep of my 80-10 EFHW with 12801 data
points on the PC app. Wow!
The Smith Chart and SWR show why the EFHW is so popular. SWR <= 2:1 over
the whole range!

On Mon, Dec 20, 2021 at 1:25 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Mon, Dec 20, 2021 at 09:50 AM, Bo W4GHV wrote:


I just obtained mine, so forgive my lack of knowledge.
I thought it only had 100 data points? How do you scan a wide range?
But, I just read you can do this if it is connected to a PC using the
software.

Bo W4GHV since '54
I suggest you read the Absolute Beginners Guide in the Files section of
this group. Also check out the group Wiki.

Roger






Re: #general_vna Saving to SD card #general_vna

joe bell
 

Hi Chris

the screen shots show the correct driver and the correct hex in the uart, plus the QT version using the same set up always connects as does the app from 1 of 11. This tends to make me think it is an app problem.

Interestingly, if you view the screen output of the ini file, entering a non existent port number results in an immediate error message, however entering the allocated port number shows nothing, program just hangs and a second attempt to connect to the port crashes program.

joe

On 21/12/2021 10:10, Chris Gardner via groups.io wrote:
I had something similar happen... Once windows decides the type of device (right or wrong), it assigns a driver. Often, when you try to load the correct driver, windows will insist it already has the "best" driver.
Perhaps the Nano had been connected, before the required driver was loaded first, that can cause windows to load the incorrect driver.
I used a program called Zadig Available here ===> Select show all devices, find the one in question, then load the generic usb driver
Next load the correct ST Microdevices driver.


Re: #general_vna Saving to SD card #general_vna

 

I had something similar happen... Once windows decides the type of device (right or wrong), it assigns a driver. Often, when you try to load the correct driver, windows will insist it already has the "best" driver.
Perhaps the Nano had been connected, before the required driver was loaded first, that can cause windows to load the incorrect driver.
I used a program called Zadig Available here ===>
Select show all devices, find the one in question, then load the generic usb driver
Next load the correct ST Microdevices driver.


Re: #general_vna Saving to SD card #general_vna

joe bell
 

Further

the COM3 port allocated when nano is connected details show as ports\VID\04B4&PID_008

joe


Re: #general_vna Saving to SD card #general_vna

joe bell
 

Using device manager and connecting the vna unit aUSB to Uart adapter shows up

usb\vid_04B4&PID_0008&REV_001

usb\vid_04B4&pid_008

is this what you mean?


Re: Frequency accuracy

 

Think of it in golfing terms. It's like trying to putt with a 'mashie'. (personally I prefer a #2 wood to putt)

Mike C.

On 12/20/2021 1:48 PM, Dave Daniel wrote:
Remember, the difference between ¡°accuracy¡± and ¡°precision¡± is important.

Accuracy has to do with the degree to which an instrument can determine a measured value compared to the actual value, independent of the method of measurement.

Precision is the degree to which an instrument can display the actual value.
For precision, think about measuring a length; does the scale read in 10ths of an inch, 100ths of an inch? And how accurate are those markings on the scale?

DaveD

On Dec 20, 2021, at 13:18, Earle Wilkinson <earle.wilkinson@...> wrote:

?Thanks for the response will let you know the outcome


Earle D Wilkinson
(6Y5EW)

Home page:
Email address: earle.wilkinson@...
Echolink: 6Y5RA

On Mon, Dec 20, 2021, 10:21 AM Jim Lux <jim@...> wrote:

On 12/20/21 12:27 AM, Earle Wilkinson wrote:
Earle D Wilkinson
(6Y5EW)

Home page:
Email address: earle.wilkinson@...
Echolink: 6Y5RA

On Mon, Dec 20, 2021, 3:18 AM Earle Wilkinson <earle.wilkinson@...

wrote:

New at this.

I got myself an NanoVNA 2 version 4.
Everyone says best thing ever happened.

Better than sliced cheese.

My problem is that I a sticular when it comes to accuracy.

I would like to check my club stations duplexer accuracy on 147.960 high
pass filter with 147.360 as the split on the low pass filter, that is
minus
600 kc split.

Now her is my problem I can only set my markers at 147.300 and 147.900.
Not the exact repeater frequency.

Will the difference of 60 hz make a difference in the accuracy of the
tuning insertion loss etc.

I realise that I need to be accurate at least with the 50 ohms
impedance.
Thanks for your response.
Earle D Wilkinson
(6Y5EW)

Home page:
Email address: earle.wilkinson@...
Echolink: 6Y5RA
Two issues that arise:

#1 The NanoVNA only has a limited number of frequency steps
(101,201,401, depending on which firmware and model) unless you're using
software on an external computer that does multiple scans. So, if you
set your span to, say, 147 to 148 MHz, then you'll get a measurement
every 10 kHz (with 101 points). Solution here is to use one of the many
software packages that will talk to the NanoVNA and make multiple scans
and combine them.

#2 The 28 MHz oscillator in the NanoVNA isn't necessarily accurate
enough. I don't recall the spec, but let's say it's on the order of 10
ppm (good for a TCXO) - at 147 MHz, that means it could be off by 1470 Hz.











Re: Transimission mesurements

 

Lighten up, I'm an old F*** but names don't bother me. I'm just P when somebody steals my marbles. :0)

Mike C.

On 12/20/2021 12:34 PM, Charles Young wrote:
Robin:

Rather insensitive terminology here!
"1) there is the odd Doll on this group as well as [far too many, /pro rata/] Guys¡±

Chuck Young



On Dec 20, 2021, at 6:56 AM, G8DQX list <list@...> wrote:

Jens,

1) there is the odd Doll on this group as well as [far too many, /pro rata/] Guys

2) for the technical question, imagine that there are *2* oscillators active, one at f?, one at f?+IF, where IF is an intermediate frequency and f? is the measurement frequency. Then, as square waves, the measurement oscillator will produce frequencies f?, 3f?¡­, and the local oscillator will produce frequencies f?+IF, 3f?+3IF¡­ Then at the fundamental frequency, the difference frequency is IF, but when the third harmonic products mix, the difference frequency is 3IF. The products at 3IF will be rejected by the post mixer bandpass filter.

3) similar arguments apply when harmonic mixing is employed, such as for the 300?MHz - 900?MHz range. Note in this case, that there will be an unwanted product from the fundamental frequencies at ?IF (hence the use of a bandpass, rather than lowpass, filter) and the 5^th harmonic at 1?IF.

Also note the reducing power in the harmonics, thus doubly reducing the mixer products to be measured. The fact that any of this works is a triumph of human ingenuity and DSP.

4) Identifying all the frequencies and corresponding mixing products for n^th harmonic operation is left as an exercise for the interested reader!

HTH, 73, Stay Safe,

Robin, G8DQX

PS: For this sort of hybrid analogue & digital machine, often the block diagram is more informative than the circuit (schematic) diagram. The actions of the software are also key components.

On 20/12/2021 11:11, Jens M?ller wrote:
Hello Guys,

I've one question which puzzles me, and was unable to find information neihter in the forum nor in the Wiki.
Since the NanoVNA outputs a rectagular signal which's harmonics are not neglectable and has no selective input (what I can see from the schematic is broadband), how can the S12 and S21 measurements be accurate as all the harmonics of the output will go into the mesurement at the input.

What do I have overseen?

Thanks for bringing me on the right track

Jens DF9HJ






Re: #general_vna Saving to SD card #general_vna

 

NanoVNA Saver search for this USB devices
USBDevice(0x0483, 0x5740, "NanoVNA"),
USBDevice(0x16c0, 0x0483, "AVNA"),
USBDevice(0x04b4, 0x0008, "S-A-A-2"),

you can see this in device id (details):
Ports\VID_04B4&PID_0008

Check it for your device


Re: #general_vna Saving to SD card #general_vna

joe bell
 

Upon checking the link to ST driver is version I already loaded.

I double checked the addition of USB port when nanovna connected.

this is before connection




and this is after connecting nanovna


Re: #general_vna Saving to SD card #general_vna

joe bell
 

You say wrong port, but same port number works with QT version and app from one-of-eleven? same driver.

I just grabbed st driver from web and installing now

cheers

joe