Re: [nanovnav2] 450-OHM WINDOW LINE........OR IS IT?
Yes, it is, Jim. We're not dealing with metamaterials!! Too many things
going on in my 74 YO gray matter. With a measured Vp of 0.87, the
effective ¦År should be 1.07.
Dave - WLEV
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On Thu, Feb 25, 2021 at 11:24 PM Lux, Jim <jim@...> wrote: On 2/25/21 2:58 PM, David Eckhardt wrote:
I was doing some modeling using SimSmith and measured values of the
shack end of my 450-foot long doublet fed with (mostly) 450-ohm window
line.
I was not getting what I would expect, so I measured the Zc of a
7.17-foot length of (claimed) 450-ohm window line. Measured values of
total L and C follow:
8.2 MHz 34.8 pF 3.51 ?H Calc Zc: 318 ohms 4.85 pF / Ft
2.6 MHz 32.4 pF 3.07 ?H Calc Zc: 308 ohms 4.5 pF / Ft
Measured wire center-to-center spacing is 0.85-inches
Wire is stranded AWG #16 stranded copper weld
Using an ¦År of 0.91, the physical parameters indicate Zc more like 430
to 440 ohms
using the calculator at:
<>
It is quite a feat to get a relative epsilon less than 1 <grin> You can
do it with ionized plasmas, but I suspect that's not what you have.
I'd guess window line, which is 90% "open space" would have an er of
around 1.2 or 1.3
Does that make your numbers come out closer?
I'm a little suspicious of that calculator - AWG 16 needs to be an inch
apart for 450 ohms with er=1
Using this one:
51 mil diameter (AWG 16), 850 mil spacing, er=1.1 -> 400 ohms
.22 pF/inch -> 2.64 pF/ft
So, what I have isn't 450 ohms as claimed.
REQUEST: If others have a length of this standard window line, could
you please make measurements and confirm or deny my measurement that
indicate a Zc more like 310 ohms instead of the claimed 450-ohms?
--
*Dave - W?LEV*
/*Just Let Darwin Work*/
--
*Dave - W?LEV*
*Just Let Darwin Work*
|
Re: [nanovnav2] 450-OHM WINDOW LINE........OR IS IT?
Yes, much better calculator. Yes, I biffed it a bit on ¦År. Wireman gives
Vp = 0.91. I measure 0.87 which yields an ¦År of 1.07.
But given my measurements of L and C for 7.17 feet, I still see more like
Zc = 310 ohms, not 450.
Dave - W?LEV
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On Thu, Feb 25, 2021 at 11:24 PM Lux, Jim <jim@...> wrote: On 2/25/21 2:58 PM, David Eckhardt wrote:
I was doing some modeling using SimSmith and measured values of the
shack end of my 450-foot long doublet fed with (mostly) 450-ohm window
line.
I was not getting what I would expect, so I measured the Zc of a
7.17-foot length of (claimed) 450-ohm window line. Measured values of
total L and C follow:
8.2 MHz 34.8 pF 3.51 ?H Calc Zc: 318 ohms 4.85 pF / Ft
2.6 MHz 32.4 pF 3.07 ?H Calc Zc: 308 ohms 4.5 pF / Ft
Measured wire center-to-center spacing is 0.85-inches
Wire is stranded AWG #16 stranded copper weld
Using an ¦År of 0.91, the physical parameters indicate Zc more like 430
to 440 ohms
using the calculator at:
<>
It is quite a feat to get a relative epsilon less than 1 <grin> You can
do it with ionized plasmas, but I suspect that's not what you have.
I'd guess window line, which is 90% "open space" would have an er of
around 1.2 or 1.3
Does that make your numbers come out closer?
I'm a little suspicious of that calculator - AWG 16 needs to be an inch
apart for 450 ohms with er=1
Using this one:
51 mil diameter (AWG 16), 850 mil spacing, er=1.1 -> 400 ohms
.22 pF/inch -> 2.64 pF/ft
So, what I have isn't 450 ohms as claimed.
REQUEST: If others have a length of this standard window line, could
you please make measurements and confirm or deny my measurement that
indicate a Zc more like 310 ohms instead of the claimed 450-ohms?
--
*Dave - W?LEV*
/*Just Let Darwin Work*/
--
*Dave - W?LEV*
*Just Let Darwin Work*
|
Re: 450-OHM WINDOW LINE........OR IS IT?
I always get a kick out of it when someone mentions SimSmith. The Sim Smith Bridge in Indiana was built in 1883. (OK, I'm in a weird mood today.) :-) Zack W9SZ On Thu, Feb 25, 2021 at 4:59 PM David Eckhardt <davearea51a@...> wrote: I was doing some modeling using SimSmith and measured values of the shack
end of my 450-foot long doublet fed with (mostly) 450-ohm window line.
I was not getting what I would expect, so I measured the Zc of a 7.17-foot
length of (claimed) 450-ohm window line. Measured values of total L and C
follow:
8.2 MHz 34.8 pF 3.51 ?H Calc Zc: 318 ohms 4.85 pF /
Ft
2.6 MHz 32.4 pF 3.07 ?H Calc Zc: 308 ohms 4.5 pF / Ft
Measured wire center-to-center spacing is 0.85-inches
Wire is stranded AWG #16 stranded copper weld
Using an ¦År of 0.91, the physical parameters indicate Zc more like 430 to
440 ohms
using the calculator at:
So, what I have isn't 450 ohms as claimed.
REQUEST: If others have a length of this standard window line, could you
please make measurements and confirm or deny my measurement that indicate a
Zc more like 310 ohms instead of the claimed 450-ohms?
--
*Dave - W?LEV*
*Just Let Darwin Work*
<> Virus-free. www.avast.com <> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
|
Re: [nanovnav2] 450-OHM WINDOW LINE........OR IS IT?
On 2/25/21 2:58 PM, David Eckhardt wrote: I was doing some modeling using SimSmith and measured values of the shack end of my 450-foot long doublet fed with (mostly) 450-ohm window line.
I was not getting what I would expect, so I measured the Zc of a 7.17-foot length of (claimed) 450-ohm window line.? Measured values of total L and C follow:
? ?? 8.2 MHz ? ? 34.8 pF 3.51 ?H ? ? Calc Zc:? 318 ohms???? 4.85 pF / Ft
? ?? 2.6 MHz ? ? 32.4 pF 3.07 ?H ? ? Calc Zc:? 308 ohms???? 4.5 pF / Ft
Measured wire center-to-center spacing is 0.85-inches
Wire is stranded AWG #16 stranded copper weld
Using an ¦År of 0.91, the physical parameters indicate Zc more like 430 to 440 ohms
?????? using the calculator at: <>
It is quite a feat to get a relative epsilon less than 1 <grin> You can do it with ionized plasmas, but I suspect that's not what you have. I'd guess window line, which is 90% "open space" would have an er of around 1.2 or 1.3 Does that make your numbers come out closer? I'm a little suspicious of that calculator - AWG 16 needs to be an inch apart for 450 ohms with er=1 Using this one: 51 mil diameter (AWG 16), 850 mil spacing, er=1.1 -> 400 ohms .22 pF/inch -> 2.64 pF/ft So, what I have isn't 450 ohms as claimed.
REQUEST:? If others have a length of this standard window line, could? you please make measurements and confirm or deny my measurement that indicate a Zc more like 310 ohms instead of the claimed 450-ohms?
--
*Dave - W?LEV*
/*Just Let Darwin Work*/
|
Re: Portable Analyzer Options
Mike: 100kHz steps is pretty coarse resolution, some bands might only have 1 to 3 points with lots of wasted points between ham bands; you might want to take narrower sweeps of the bands you plan to use and store several calibrations so as not to spread the measurement points so thin. Or just bring the calibration standards along and calibrate on the fly; a 1-port reflection calibration is only 3 measurements.
Instead of buttons see how you like using the touch screen, it works well with a stylus (a mechanical pencil works well and can be used for notes and logging) and I find it faster.
73, Don N2VGU
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450-OHM WINDOW LINE........OR IS IT?
I was doing some modeling using SimSmith and measured values of the shack
end of my 450-foot long doublet fed with (mostly) 450-ohm window line.
I was not getting what I would expect, so I measured the Zc of a 7.17-foot
length of (claimed) 450-ohm window line. Measured values of total L and C
follow:
8.2 MHz 34.8 pF 3.51 ?H Calc Zc: 318 ohms 4.85 pF / Ft
2.6 MHz 32.4 pF 3.07 ?H Calc Zc: 308 ohms 4.5 pF / Ft
Measured wire center-to-center spacing is 0.85-inches
Wire is stranded AWG #16 stranded copper weld
Using an ¦År of 0.91, the physical parameters indicate Zc more like 430 to
440 ohms
using the calculator at:
So, what I have isn't 450 ohms as claimed.
REQUEST: If others have a length of this standard window line, could you
please make measurements and confirm or deny my measurement that indicate a
Zc more like 310 ohms instead of the claimed 450-ohms?
--
*Dave - W?LEV*
*Just Let Darwin Work*
|
Re: Pitfalls of measuring components with the NanoVNA
#measurement
I know it takes a long time to write such a detailed and informative post. It took pretty much my entire morning. But I have to admit that my morning started around 11 AM! ;-)
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Re: Portable Analyzer Options
You get 2 out of 3 with the NanoVNA-H4. With the latest software you get 401 points and there is an SD card storage capability. On mine you have to file the case slot to access the SD card connector but maybe Hugen is now shipping with the slot cut already.
One of the big issues is seeing the screen in bright sunlight. I prefer my RigExpert for outside work.
Roger
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Portable Analyzer Options
I am preparing for portable operations once the weather gets warmer. I want to take along a nanovna to troubleshoot issues on the field. One important requirement is the scrolling and input control has to be buttons, not the thumbwheel switch so that left me with two options, the nanovna-F version 3.1 form Deepelec.com and the nanovna-SAA-2N which I purchased form R&L Electronics. Both are in metal cases which is an asset for filed work. I use BNC connectors so I Install adapters on each unit and use a BNC calibration kit.
I can use the command set or a computer program to configure the nanovna but I do not want to use a laptop or smartphone in the field, just a standalone unit.
Some other requirements and my observations are as follows:
- Frequency Range 1 to 30 Mhz in 100kHz steps (301 segments)
nanovna-F : 101 segments - have to use 3 RECALL settings for resolution
nanovna-SAA-2N : 201 segments - have to use 2 RECALL settings for resolution
- TDR functionality : both units support function via TRANSFORM settings
- Save and examine results
nanovna-F : STORAGE S1P and S2P
nanovna-SAA-2N : no storage
Are there any other models which have button controls, at lease 301 segments and save measurement to storage?
Thanks,
Mike N2MS
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Look like broken LCD module (or bad connection). Blue LED flash - mean normal scan, as i see your device worked, and can send data to CPU over USB.
Problem in LCD module (or in SPI bus), try check it connection.
Check all data lines (SPI, CS, Reset), power lines. See NanoVNA scheme.
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I've put as many DFU files that i can find looking through the files section on here, put them into a folder and trying them one by one.
Just for the fun of it and scientific experimentation.
Regards, James.
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I must admit Richard, I thought I was going to brick this little device but up to now, I've not managed too.
But I can get very similar results to you with the white screen.
I'd keep at it until you really can't take any more Hi Hi.
Regards, James.
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Not all will work on your device Richard from what I believe so keep trying.
I did try some recently and had the same result as you.
Flashed it manually and the white screen stayed there.
Keep trying as there are many to choose from but finding the right one for your device could take a while I would say.
The NanoVNA-App software seems to be able to make that decision for you though and selects the right one for your device.
I'm still learning myself as I've only just started to dabble with flashing the device so I'm open to the experts on here.
Kind regards, James.
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Hi Richard, its an option when you run the NanoVNA-App software. This latest software has it built in. When you run the NanoVNA-App software and select the two points button at the top of the page, another window drops down where you can select one of two firmware for the device. There are three to choose from but it will only let you use two of them as it knows which device is connected to the pc. Once your NanoVNA device is in DFU mode, you can literally press the firmware version button and the rest is automated. You can manually flash from a folder saved to your drive any of the many DFU's written for the device if you want too. There are plenty to choose from and can be found in the files section of the groups. This is where i got the H4 version that i tried. Link to many can be found here too /g/nanovna-users/files/Firmware/All%20%28known%29%20publicly%20available%20NanoVNA%20DFU%20files%20from%20May%205,%202019%20through%20to%20Sept%2029,%202019 Hope it helps. Kind regards, James.
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all ok found it and 1.045 in files section here...
tried both, loaded 3 times each and recycled power got the same result each time
natta! nothing on the display...
goo try
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On Thu, Feb 25, 2021 at 10:09 AM, James Anderson wrote:
DiSlord H v1.0.39
James where did you download it from...you got a link please
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Re: Pitfalls of measuring components with the NanoVNA
#measurement
Manfred,
I know it takes a long time to write such a detailed and informative post. Thanks for posting!
Regards - Roger
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Re: Pitfalls of measuring components with the NanoVNA
#measurement
This was a fantastic read! Thanks Manfred!
I used type 43 material to wind a common mode choke for HF frequencies recently. It seems to give about 30 dB attenuation with small signal stimulus, however, I was wondering how it would behave under power.
Regards,
Gregg
--
VE6WGM
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Re: Nano VNA: An Antenna Stethoscope ( pdf file latest edition de k3eu )
Barry Thank you for that wonderful line " Each time I give this talk, I
learn more about what the hurdles are. I find, as a teacher, we can "say
the words and answer multiple choice exams without any REAL understanding".
I took out a lengthy period and left the Audio Engineering industry and
started teaching Electronics & Sound Engineering to Level IV. The first
book I read in preparation was Isaac Asimov's Guide to Science. I always
had in my mind... "What happens if that kid at the front asks "Yeah but
really Why???".
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On Thu, 25 Feb 2021 at 17:11, Dave Daniel <kc0wjn@...> wrote: 365 MB
On 2/25/2021 10:32 AM, Bob wrote:
What is the size of the mp4 file?
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Hello Gyula and thank you for the reply and the tera term and putty info.
I¡¯ve watched a couple of videos after posting too but thank you.
I was just trying a few things out to try and resemble Richards predicament.
I was just curious as to how the smaller Nano that I have would react to me fooling around with it.
I¡¯d read somewhere that it was difficult to ¡°brick¡± it so did some experimenting.
And for what they cost, even if I did brick it, it wouldn¡¯t be the end of the world.
I¡¯m just hoping that it is firmware based and not hardware for Richard.
Very kind regards, James.
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On 25 Feb 2021, at 18:11, Gyula Molnar <gyula.ha3hz@...> wrote:
?Hi James,
I think you choose the firmware versions based on your idea and meanwhile mix the firmware written for the 2.8 "and 4" (3.95 ") versions. Yet these should not be confused with each other because they use a different microprocessor. They will not work with the firmware written for the other.
For example, you are writing here: /g/nanovna-users/message/20975 -H4 you are experimenting with firmware. Do not do it.
You may not allow the other to charge immediately.
Managing terminal programs For PuTTY, the Port, Speed ??and Serial markings must be set in the Configuration. You can find their information in PC Device Manager when you connect to your device.
All three data must match for PC and PuTTY.
I assume that the driver is already on the PC, so if the connection is successful, it is advisable to type the word 'help' when the cursor is flashing, because in response you will see the possible commands.
In the wiki or files folder you will find a list of possible consol commands and what commands they accept.
You can also find more on the website of the creator of the given program.
73, Gyula HA3HZ
--
*** If you are not part of the solution, then you are the problem. ( ) ***
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Donald S Brant Jr
Roger Need
Gregg Messenger VE6WGM