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.
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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
|
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
|
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
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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
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Anyway you use wrong Port (this for USB to TTL dongle) Find USB Serial Port from CypressSerial
|
My nano vna states SAA-2N,? HW version V2_2?? manufactured by Zeenko
if you need other information please state where to find it
joe
|
Just for understand - you mean NanoVNA-H or H4 ??
Not V2 model?
My last post for NanoVNA-H or H4
|
I see CDC to USART adapter - this not NanoVNA port NanoVNA port must have name STMicroelectronics Virtual COM Port Driver:
|
Hi DisLord, thanks for coming back to my shout for help
I installed the nanovna-save on win10 no problem, but I wanted to use an older laptop using win7 and that will not connect to the allocated USB port at all. Even typing the port number into the saver port box does not work.
Running the QT version on the same machine connects every time! and also running the app by one-of-eleven connects every time.
Anyone any ideas?
Using Dell latitude laptop with Win 7 & SP1
I also loaded up the .net framework and VBS just to cross that off the list.
I installed the Cypress driver from the? installer
Plugging in the vna and checking com ports i get
USBD Views
After connection attempt has failed this message is added to ini file
The .ini file has no file call? so I am left asking the forum for ideas
my nano save is ver 0.2.2.1
Regards
joe
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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
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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.
|
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: Transimission mesurements
Thanks Robin,
vy 73 Jens
Am 20.12.2021 um 12:56 schrieb G8DQX list:
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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
|
Thanks for the response will let you know the outcome
Earle D Wilkinson
(6Y5EW)
Home page:
Email address: earle.wilkinson@...
Echolink: 6Y5RA
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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.
|
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
|
Re: Transimission mesurements
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
toggle quoted message
Show quoted text
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
|
Interesting video by W2AEW on this subject
"How to tune a duplexer with a NanoVNA V2plus4 | is it possible?"
Roger
|
The attached image indicates you are measuring from 50 to 52 MHz, not 1.9
to 450 MHz.
Dave - W?LEV
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On Mon, Dec 20, 2021 at 8:52 AM JF1XCV <hs@...> wrote: Hi All!
I am now evaluating a 1:6 UNUN with NanoVNA that I bought quite recently.
The UNUN is made of two stacked FT240-61 and 1.6mm copper wire with 100pF
capacitor in the primary. To measure SWR, a 1800 ohm carbon resistor is
soldered in the secondary side. To my surprise, SWR is 1.0 from 1.9MHz to
430MHz. I suspect I misunderstood how to measure SWR with NanoVNA. I am
attaching the screen of NanoVNA Saver. Any comments are welcome. Thank you.
Henry JF1XCV
--
*Dave - W?LEV*
*Just Let Darwin Work*
|
Thanks, DiSlord for this! It's awfully close, and granted, for precision accuracy remember that we're comparing a $50-$75 device against oscilloscopes or spectrum analyzers which cost many times that....You get what you pay for, most of the time anyway. Tuning duplexer cans isn't for the faint of heart, but the NanoVNA will get you close enough to get into the ballpark.
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On Monday, December 20, 2021, 10:31:52 AM EST, DiSlord <dislordlive@...> wrote: On Mon, Dec 20, 2021 at 07:21 AM, Jim Lux wrote:
#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.
( #window-197633454 )
My fw allow made internal 26MHz TCXO correction (see CONFIG->EXPERT SETTING->TCXO) Power on device, set 26MHz CW output Wait near 5-10min for device warm Measure output frequency Enter this value as TCXO Save confog. Now as minimum up to 100MHz Nano have only +-2Hz error. (Error bigger on more high frequency)
|
On Mon, Dec 20, 2021 at 07:21 AM, Jim Lux wrote:
#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.
( #window-197633454 )
My fw allow made internal 26MHz TCXO correction (see CONFIG->EXPERT SETTING->TCXO) Power on device, set 26MHz CW output Wait near 5-10min for device warm Measure output frequency Enter this value as TCXO Save confog. Now as minimum up to 100MHz Nano have only +-2Hz error. (Error bigger on more high frequency)
|
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.
|
Mike C.
Roger Need
Bo W4GHV