Re: Proper way to measure length of _Window_Line_?
I've measured windowline many times using the NANO - something I can not easily accomplish with the HP 8753C. Be sure the NANO is not connected to any conducting cabling, chargers, USB cables, or sitting on or near anything conducting. At HF frequencies the NANO is small enough to not influence measurements. However, if it is connected to anything conducting, it is no longer "small" as a function of frequency / wavelength. The attachment indicates you have connected the NANO to a PC. The NANO effectively becomes much larger at RF frequencies as its connected to: 1) the USB cable, 2) the PC, and 3) the house wiring, and finally, 4) the power grid. This will greatly influence correct readings of windowline. Measurements must be made with the NANO alone. Dave - W?LEV On Tue, Feb 15, 2022 at 4:40 PM Kevin Zembower via groups.io <kevin= [email protected]> wrote: I'm wondering if the correct way to measure the length of window line
with a NanoVNA is fundamentally different than that of measuring coax.
I'm following the method described by Arie
(/g/nanovna-users/message/26832). I have 5.175m of "JSC
1320 300 Ohm Ladder Line 300 Ohm 20 AWG / 7 Strands Bare Copper". That's
a quarter wavelength of 20.7m, or a frequency of 14.5MHz.
The first step is to sweep it to determine the velocity factor. Yet,
when I sweep from 12-17MHz, I get the Smith chart attached. There's no
point when the impedance is close to zero.
Am I doing something wrong (most probable), or is measuring the length
of window line with an NanoVNA fundamentally different than measuring coax?
Thanks for your advice and suggestions.
-Kevin
KC3KZ
-- *Dave - W?LEV* *Just Let Darwin Work*
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Proper way to measure length of _Window_Line_?
I'm wondering if the correct way to measure the length of window line with a NanoVNA is fundamentally different than that of measuring coax. I'm following the method described by Arie ( /g/nanovna-users/message/26832). I have 5.175m of "JSC 1320 300 Ohm Ladder Line 300 Ohm 20 AWG / 7 Strands Bare Copper". That's a quarter wavelength of 20.7m, or a frequency of 14.5MHz. The first step is to sweep it to determine the velocity factor. Yet, when I sweep from 12-17MHz, I get the Smith chart attached. There's no point when the impedance is close to zero. Am I doing something wrong (most probable), or is measuring the length of window line with an NanoVNA fundamentally different than measuring coax? Thanks for your advice and suggestions. -Kevin KC3KZ
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Re: PC Won't Recognize Unit in DFU Mode so Can't Update Firmware
Hi , some time ,is it necessary to force the installation of the STM drivers as wrote on readme.txt , inside the directory of the
en.stsw-stm32102.
/ (C) COPYRIGHT 2018 STMicroelectronics
* File Name : readme.txt
* Author : MCD Application Team
* Version : V1.5.0
* Date : 02/05/2018
* Description : read me file for Virtual COM Port driver
* THE PRESENT SOFTWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.
* AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,
* INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE
* CONTENT OF SUCH SOFTWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING
* INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
****/
Last version
- V1.5.0 - 02/05/2018
Supported OS
+ Windows 98SE, 2000, XP, Vista, Seven, 8.x (x86 & x64 Windows platforms)
Contents
*
+ VCP_V1.5.0_Setup_W7_x86_32bits.exe : Setup file to Copy required files for Win7 x86
+ VCP_V1.5.0_Setup_W7_x64_64bits.exe : Setup file to Copy required files for Win7 x64
+ VCP_V1.5.0_Setup_W8_x86_32bits.exe : Setup file to Copy required files for Win8 x86
+ VCP_V1.5.0_Setup_W8_x64_64bits.exe : Setup file to Copy required files for Win8 x64
+ version.txt : History of versions
+ readme.txt : This file
How to use
1- Uninstall previous versions (Start-> Settings-> Control Panel-> Add or remove programs)
2- Run your "VCP_V1.5.0_Setup_W7_x86_32bits.exe" or "VCP_V1.5.0_Setup_W7_x64_64bits.exe" or "VCP_V1.5.0_Setup_W8_x86_32bits.exe" or "VCP_V1.5.0_Setup_W8_x64_64bits.exe" depending on your machine OS
if you like to force the driver install , any time after the first install :
3- Go to Your installation directory - Example, C:\Program Files (x86)\STMicroelectronics\Software\Virtual comport driver
4- Go to Your OS version directory ([Win7] or [Win8])
+ Then :
- Double click on dpinst_x86.exe if you are running a 32-bits OS version
- Double click on dpinst_amd64.exe if you are running a 64-bits OS version
+ Follow the instructions.
**** (C) COPYRIGHT 2018 STMicroelectronics END OF FILE*
Maurizio
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Re: PC Won't Recognize Unit in DFU Mode so Can't Update Firmware
This solution solved my issue, which was exactly the same as OP. Thank you sir!!
Tim NC0Q
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On Fri, Jan 22, 2021 at 04:55 PM, Michael Brickell VE3TKI wrote:
I have 3 laptops, two running Windows 10, and one running Window 7. I was
able to install the v1.0.39 firmware for my H4 nanoVNA on the Windows 7 laptop
but not the Windows 10 ones. When I ran the DFuse v3.0.6 program I did not
see anything in the Available DFU Devices List. The problem was that the
bootloader driver did not install with the DFuse Demo v3.06 program.
I then downloaded the STM Bootloader Driver package from
, and
installed the amd64.exe driver on the Windows 10 laptops. Having done this I
found that when the nanoVNA is placed in DFU mode and connected via the USB
cable, an ¡°STM Device in DFU Mode¡± appears in the list of USB Controllers
in Device Manager.
When I run the DFuse Demo v3.0.6 program I now see ¡°STM Device in DFU
Mode¡± in the Available DFU Devices List , and the new firmware installs
properly.
Michael Brickell VE3TKI
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Re: Need help with SD card problems
David,
The SD card routines have been tweaked to work with most TF cards in SPI mode.
Unfortunately, not all cards support that mode of operation.
Most newer cards do support SPI mode.
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On Monday, February 14, 2022, 11:45:07 a.m. EST, David Rounds <groups@...> wrote:
I could not find any of my SanDisk 16gb cards that would work.
Switched to a Samsung 32gb and it worked perfectly.
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Re: Need help with SD card problems
I could not find any of my SanDisk 16gb cards that would work.
Switched to a Samsung 32gb and it worked perfectly.
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On 2/13/22 11:27 PM, Maurizio IZ1MDJ wrote: Hi , in my opinion , calibrate the S11 port , with 20 dB of attenuation applied , make non sense .
Maurizio
Yes, I'd put the 20 dB pad on the UUT output (i.e. the CH1 port, not the CH0 port).? Then you do a calibration (with the pad in place).? Measure your UUT, add 20 dB to the S21 magnitude. You could also measure the pad separately (with a conventional SOT calibration), measure the UUT and pad, then do the arithmetic.
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I think Jim was saying two things:
1) Calibrate it normally and then measure a known device, like e a 20dB attenuator, and see if you get a sane result.
2) If measuring a (say) 20dB amplifier, put 20dB of attenuation after it, so you don¡¯t overload the input.
73, Willie N1JBJ
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On Feb 14, 2022, at 2:27 AM, Maurizio IZ1MDJ <redifon500@...> wrote:
Hi , in my opinion , calibrate the S11 port , with 20 dB of attenuation applied , make non sense .
Maurizio
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Hi , in my opinion , calibrate the S11 port , with 20 dB of attenuation applied , make non sense .
Maurizio
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On 2/13/22 3:37 PM, Alan Brown via groups.io wrote: Trying to use log mag and not working now.
I think I overload S21 with more then 10db.
What is the fix anyone now?
I¡¯m hoping some simple right at the port If you check with a thru and/or a pad, do you get the right values (i.e. did you not damage anything). You can put 20 dB attenuation at the output of your amplifier under test. Calibrate (Short, open, thru) using the pad.
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Trying to use log mag and not working now.
I think I overload S21 with more then 10db.
What is the fix anyone now?
I¡¯m hoping some simple right at the port
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For information only:
Ham-Con this year will be both in-person and online. It is scheduled on Feb, 26th, 2022. Before Feb 20th, entrance is $6, after it is $10. See all the information on
Thanks
Bob, k1bif
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Re: Proper way to measure cable length
Did anyone read my initial reply to this thread? All this was there, but
not using the TDR.
Dave - W?LEV
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On Sat, Feb 12, 2022 at 7:04 PM Timothy Cash <cash.tim@...> wrote: This one is very easy to answer as a cable engineer having used both TDR
and OTDR Test Equipment in the past.
All you do is get an exact known length of cable, attach it to your TDR,
dial in a vp UNTIL you get the exact length on the instrument.
That is the vp by virtue of test and measurement.
OR
Follow this guide:
On Sun, Feb 6, 2022 at 11:33 PM lobos305 via groups.io <lobos305=
[email protected]> wrote:
What velocity factor would you use to measure the physical length of a
cable when you don't know the cable type?
Pat
--
Tim Cash | Senior RF/Optical Systems Engineer
cash.tim@...
--
*Dave - W?LEV*
*Just Let Darwin Work*
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Re: Proper way to measure cable length
This one is very easy to answer as a cable engineer having used both TDR and OTDR Test Equipment in the past. All you do is get an exact known length of cable, attach it to your TDR, dial in a vp UNTIL you get the exact length on the instrument. That is the vp by virtue of test and measurement. OR Follow this guide: On Sun, Feb 6, 2022 at 11:33 PM lobos305 via groups.io <lobos305= [email protected]> wrote: What velocity factor would you use to measure the physical length of a
cable when you don't know the cable type?
Pat
-- Tim Cash | Senior RF/Optical Systems Engineer cash.tim@...
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Re: Proper way to measure cable length
Hi Bob,
What I wrote about the 150m is not a calculation of a cable length. I was showing that the electrical length is 200m for a physical length of 150m. :-)
About the quality of the nanoVNA H3.2 that I have: you have to be careful. There's no temperature compensation for example. But on the other hand, I was able to measure resistance <0.5 ohm with good accuracy in the HF range and I also tested the nano on 10kohms. Spot on. But I needed some calculus to get there.
In several articles I have explained how to measure those kind of impedances with the nano. The ways to do that are well known in the professional world, but not to hamradio guys/galls of which I am one ;-)
Arie
Op 12-2-2022 om 01:47 schreef Bob Ecclestone:
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For the newbies amongst us, you will find if you MULTIPLY the Electrical Length by the Velocity Factor *(VF) you will get the correct Cable Length.
RF slows down as it travels along a cable compared to its speed in free space, about 300,000,000Kms/sec or 300m per microsecond.
In the example Arie gives, The Cable Length would be 150 * 0.78 = 117m (not ~200m). Hopefully enough
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Re: Proper way to measure cable length
On Tue, Feb 8, 2022 at 02:16 AM, Arie Kleingeld PA3A wrote:
As an example:
- the measured frequency = 11.7 MHz
- a full wavelength for this frequency = 300 / 11.7 = 25,64m
- a quarter of this is: 25,64 / 4 = 6,41m
So the electrical length of the 5m line = 6,41m and physical length = 5m
Therefore the VF = 5 / 6,41 = 0.78
Now measure the unknown length of transmissionline the same way to find
the frequency where the line is a quarter wavelength long.
Sweep S11 starting at a low frequency for example 500 kHz for a long
transmissionline ** to find the quarterwave frequency. Calculate the
quarter wavelenght in meters; divide it by the VF that you found above
and then you will know the length of the line.
(** A quarter wavelength at 500 kHz is 600m / 4 = 150m and taking into
account the VF, the electrical length will be 150/0,78 = nearly 200m,
should be enough :-)? )
Boy, the guys at CERN should have bought a NanoVNA and used some fancy math instead of building the Large Hadron Collider! That way they could achieve 1.28C for 10's of Euros instead of Billions! (Calculated Cable Length 200 / Electrical length 150 = 1.28) Sorry Arie, easy enough mistake to make. I joined the group a short while ago and am very impressed by the wealth of knowledge and advice out there. So thanks to all contributors. When I saw this post, I was sure someone would reply straight away, but nobody did. I am only doing so to help those who are new to Amateur Radio and/or transmission line theory. The method for determining the Velocity Factor (VF) in the example above is correct. (And very well explained) For the newbies amongst us, you will find if you MULTIPLY the Electrical Length by the Velocity Factor *(VF) you will get the correct Cable Length. RF slows down as it travels along a cable compared to its speed in free space, about 300,000,000Kms/sec or 300m per microsecond. In the example Arie gives, The Cable Length would be 150 * 0.78 = 117m (not ~200m). Hopefully enough :-) Cheers...Bob VK2ZRE
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Re: Screen reader compatible nanovna software for sight impaired
Hey Daniel:
Yes, there is an accessible piece of software for the NanoVna built by a member of this list Bruce KC1FSZ.
I am also a blind op and now use Bruce's software very effectively with my NanoVNA V4.
You or your friend can get the software here:
It uses a program to allow an interface to HTML and you can use a regular web browser to access the sweep functions for SWR and impedance. Bruce is still developing it to include more of the NanoVNA functions.
I use NVDA and google chrome to access it and everything works very well indeed.
73
Colin VA6BKX
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On 2022-02-10 3:35 p.m., Daniel Young wrote: Hello I have a white stick operator friend who has a talking kenwood radio, uk amplifier screen reader compatible linear.
He would like to know if there is any suitable windows software.
I tried NVDA Screen reader he uses and it seems tabbed and reading results in NanoVNA-APP.exe reporting OneOfEleven and not the buttons- which is a shame
Any suggestions gratefully received
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Screen reader compatible nanovna software for sight impaired
Hello I have a white stick operator friend who has a talking kenwood radio, uk amplifier screen reader compatible linear.
He would like to know if there is any suitable windows software.
I tried NVDA Screen reader he uses and it seems tabbed and reading results in NanoVNA-APP.exe reporting OneOfEleven and not the buttons- which is a shame
Any suggestions gratefully received
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Re: Using NanoVNA to measure receive antenna port impedance
#measurement
Great, thanks!
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On Feb 10, 2022, at 2:01 PM, Arie Kleingeld PA3A <pa3a@...> wrote:
Hi Andy,
I understand that you are talking about a crystal radio being an LC-circuit, a diode plus capacitor and a headset?
You could measure the imput impedance of that receiver. Thing is that a strong signal of a VNA could drive the diode that it would take current. Then the VNA probably will see another impedance that when the diode was not conducting.
That is what the article was about and why I made that simple attenuators to prevent that. And also wanted to test how well my nanoVNA would cope with that.
Those simple crystal receivers usually are used in MF-range, well I did once in a while. The antenna ( most times a piece of wire) will have a pretty high impedance (resistance and also capacitive reactance) if you measure it. The input impedance of the receiver will be far off 50 ohms so thinking about 50 ohms -matching procedures is not the way to go.
Tapping the antennawire into the coil (directly of via a coupled loop) and tuning the C of the LC circuit is the way I would choose and see what happens. If you hear a lot of bandnoise when you connect the antenna and you can hear the stations you expect, you are on the right path.
That article by the way was one in a series of seven. English versions were all published in the Communicator.
73,
Arie PA3A
Op 10-2-2022 om 15:14 schreef Andrew Kurtz via groups.io:
Hi Arie, read your article with great interest. I understand my nanoVNA, I think, and I understand complex algebra and Z = R + jX. But I get VERY confused by standard radio or ham talk. I made a crystal radio over the past 2 years, and never understood why or how it would be 50 ohms. I always wanted to measure my Z, but I think the main thing the antenna signal is ¡°looking at¡± is my diode, since my tank circuit has near-infinite resistance and thus is almost an open circuit. Are you suggesting I can simply plug my nanoVNA in where my antenna usually goes and get a receiver input impedance? Also, you spent a bunch of time on an attenuator, but later (I think) you concluded you didn¡¯t need it. Why would I want one? Any other suggestions for a naive beginner? I am thinking about matching Z from antenna to receiver, but I can¡¯t measure either, and when I guess at values and then design a little LC circuit to match impedances, I find it will resonate at darn near my target f, sending my desired signal to ground!
Andy
On Feb 10, 2022, at 5:43 AM, Arie Kleingeld PA3A<pa3a@...> wrote:
Coming back on the title, how to measure...
I wrote an article about that a couple of months ago, measuring the input impedance of a Elecraft K3 receiver.
It was published in the SARC Communicator sept- Oct 2021. This is the link:
See page 43
73,
Arie PA3A
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Re: Using NanoVNA to measure receive antenna port impedance
#measurement
That was the situation when I tried that concept. Thunderstorms etc. :-)
Arie
Op 10-2-2022 om 21:32 schreef W0LEV:
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Unless you live in an extremely RFI prone and RFI polluted area, you won't
hear "antenna noise" on a crystal set.
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Alan Brown
Arie Kleingeld PA3A