On 7/27/22 9:18 AM, KENT BRITAIN wrote: Hi Christian
I do lots of antennas on fiberglass PC Board, and typically the published Er value was measured at 1 kHz,
At 2.4 GHz, Er is going to be in the 3.7-3.8 range.? You can check their spec sheets for Er vs frequency plots, but that data is not commonly provided. Most people do a test coupon, which is essentially what you're doing. You have to pay BIG Bucks for PCB material that has little change with frequency. Rogers Duroid(tm) is an example. It also has low loss at microwave frequencies - the issue is the glass in FR-4. Taconic is another brand. You can get them with epsilon all the way from 2 to 10. For the record, you have not been able to buy FR-4 for some years.? It contained a Bromide Anti-Flammability compound that was banned by RoHS.??? Yea, lots of similar stuff on the market with slightly different part numbers. Most fab houses still offer FR4 Note the epsilon they give for the various mfrs (3.2 to 3.92) whether they are brominated, I don't know - there's lots of materials that can make something fire retardant. I don't know that bromine is as much a concern as lead, which is where RoHS gets to be a big deal. has more info. Polybrominated biphenyls aren't allowed in RoHS, but that might not be a common problem. There are "FR-4 halogen free" materials too. Best way to measure the Er at 2.4 GHz, bit out of the range for most Nano's, is to design a patch antenna for 2.4 GHz and see what frequency is really resonates at.? Then back into the calculations for a patch antenna using Er's that give you the actual frequency.?? Kent
On Wednesday, July 27, 2022 at 10:49:19 AM CDT, steiniche@... <steiniche@...> wrote:
Hi
I have a NanoVNA V2 Plus4.
I am trying to validate a PCB 50 ohm transmission line (trace) to be used for 2.4 GHz Wifi.
I am using a 4 layer stack-up (1.6 mm total) with the following configuration:
L1: Signal + ground pour
Prepreg 0.21 mm
L2: Ground
Prepreg 1 mm
L3: Empty
Prepreg 0.21 mm
L4: Ground
Board is FR-4 with Er = 4.6.
I have calculated the trace parameters using Saturn PCB design as a "coplanar wave" with a plane below.
I have attached 6 board files showing the actual board (board_image.jpg), rendered board (board_render.png) and the four layers (board_lx.png) + a screenshot of the calculations from Saturn PCB (calc.png). I use the following connectors from Molex:
I have calibrated the VNA in frequency range 2 GHz to 2.8 GHz with the provided SMA cable connected, see attached cal_load.jpg and cal_thru.jpg, direct_load.png, direct_thru.png
Now I connect the PCB trace and do a S11 and S21 measurement (see s11_s21.jpg). It seems to me that the result is not particularly good (see trace_thru.png and trace_load.png).
Can any of you spot any issues with the measurement method or configuration of the board? Also, if you can provide some realistic target results for such a configuration (two connectors + 82 mm trace) that would be great.
Any help is highly appreciated.
Thanks
br
Christian
|
Mine goes blank for a short while and then opens ?
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On Wed, 27 Jul 2022, 21:58 Glen Jenkins WB4KTF, <wb4ktf@...> wrote: Hello Folks,
I am trying to install Nano-Saver for the first time. I downloaded
Version 0.4 and unzipped it to my PC.
When I run the .exe file a DOS type window opens and then NOTHING else
happens. Please advise what I am doing incorrectly.
-----
Glen Jenkins, WB4KTF, Austin, TX
|
Re: cut/lengthen vertical antenna wire
The best is Copperweld wire which is a steel wire with heavy copper plating. You get the strength and low cost of steel with the electrical conductivity and corrosion resistance of copper.
SherpaDoug, WA1UWP
|
I watched the video of how that calculator works and it is a mechanical nightmare. Yes it surely is a different kind of calculator, but God help you if for some reason it quit calculating correctly. Fred - N4CLA On Wed, Jul 27, 2022 at 5:43 PM Donald S Brant Jr <dsbrantjr@...> wrote: Those Curta calculators were the bomb for rally drivers in the '70s, but a
bit rich (they still are) for my budget. The designer came up with the
idea while he was in a WWII concentration camp IIRC.
73, Don N2VGU.
|
Also, just wait a very long time. It takes saver two or three minutes
(seems like forever) to load up all the required python stuff, after that
command window opens, especially the first time you start.
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On Wed, Jul 27, 2022, 2:23 PM Stephen W9SK <stephen@...> wrote: My guess is that you may not be opening it with administrator privileges.
Check your PC user account to see if it is a Standard or Adminstrator, and
change as necessary. If it is already Administrator, right-click the
nanavna-save exe file and select 'Run as Administrator' to see if that
cures your problem. Finally, make sure that app is white-listed in any
anti-malware software you have installed (which may include Windows
Defender).
Stephen W9SK
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Glen
Jenkins WB4KTF
Sent: Wednesday, July 27, 2022 1:59 PM
To: [email protected]
Subject: Re: [nanovna-users] nanovna-saver question
Hello Folks,
I am trying to install Nano-Saver for the first time. I downloaded
Version 0.4 and unzipped it to my PC.
When I run the .exe file a DOS type window opens and then NOTHING else
happens. Please advise what I am doing incorrectly.
-----
Glen Jenkins, WB4KTF, Austin, TX
|
Those Curta calculators were the bomb for rally drivers in the '70s, but a bit rich (they still are) for my budget. The designer came up with the idea while he was in a WWII concentration camp IIRC.
73, Don N2VGU.
|
My guess is that you may not be opening it with administrator privileges. Check your PC user account to see if it is a Standard or Adminstrator, and change as necessary. If it is already Administrator, right-click the nanavna-save exe file and select 'Run as Administrator' to see if that cures your problem. Finally, make sure that app is white-listed in any anti-malware software you have installed (which may include Windows Defender).
Stephen W9SK
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Glen Jenkins WB4KTF Sent: Wednesday, July 27, 2022 1:59 PM To: [email protected]Subject: Re: [nanovna-users] nanovna-saver question Hello Folks, I am trying to install Nano-Saver for the first time. I downloaded Version 0.4 and unzipped it to my PC. When I run the .exe file a DOS type window opens and then NOTHING else happens. Please advise what I am doing incorrectly. ----- Glen Jenkins, WB4KTF, Austin, TX
|
Hello Folks,
I am trying to install Nano-Saver for the first time. I downloaded Version 0.4 and unzipped it to my PC.
When I run the .exe file a DOS type window opens and then NOTHING else happens. Please advise what I am doing incorrectly.
-----
Glen Jenkins, WB4KTF, Austin, TX
|
Re: cut/lengthen vertical antenna wire
Hi Doug,
If you get round to experimenting with horizontal wires, bear in mind that the wire might stretch and sag under its own weight, depending on length and gauge of the wire.
It is better to use hard drawn copper wire rather than the soft drawn (annealed) type commonly encountered.
Kind regards
Ed, G8FAX
|
Hi
I remember my late Father had a White slide rule. He had. EE from UCLA. he
used at work.
Martin
N6QLh
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On Wed, Jul 27, 2022 at 8:44 AM Dave Daniel <kc0wjn@...> wrote: Ok, folks, let¡¯s take the slide rule discussion offline, even though it¡¯s
very interesting. I have a Pickett C18-T made for Collins Radio, amongst
other slide rules and enjoy yakking about them. But this group is about the
nanovna. There is, in fact at least one other group dedicated to slide
rules.
DaveD
On Jul 27, 2022, at 08:03, Donald S Brant Jr <dsbrantjr@...> wrote:
?I have a Dietzgen rule with "folded" C and D scales which enable
reading to 4 decimal places and specialized scales for solving triangles.
I also have several circular rules, including some specialized ones for
aviation complete with WWII QA stamps, and my favorite, a "Nuclear Bomb
Effects Computer, Revised Edition";
In the movie, this was used by Dr. Strangelove to calculate the half-life
of "Cobalt-Thorium G" after it was apparent that the "Doomsday Device" was
going to be triggered.
73, Don N2VGU
|
Hi Christian
I do lots of antennas on fiberglass PC Board, and typically the published Er value was measured at 1 kHz,
At 2.4 GHz, Er is going to be in the 3.7-3.8 range.? You can check their spec sheets for Er vs frequency plots, but that data is not commonly provided.
You have to pay BIG Bucks for PCB material that has little change with frequency.
For the record, you have not been able to buy FR-4 for some years.? It contained a Bromide Anti-Flammability compound that was banned by RoHS.??? Yea, lots of similar stuff on the market with slightly different part numbers.?
Best way to measure the Er at 2.4 GHz, bit out of the range for most Nano's, is to design a patch antenna for 2.4 GHz and see what frequency is really resonates at.? Then back into the calculations for a patch antenna using Er's that give you the actual frequency.?? Kent
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On Wednesday, July 27, 2022 at 10:49:19 AM CDT, steiniche@... <steiniche@...> wrote:
Hi
I have a NanoVNA V2 Plus4.
I am trying to validate a PCB 50 ohm transmission line (trace) to be used for 2.4 GHz Wifi.
I am using a 4 layer stack-up (1.6 mm total) with the following configuration:
L1: Signal + ground pour
Prepreg 0.21 mm
L2: Ground
Prepreg 1 mm
L3: Empty
Prepreg 0.21 mm
L4: Ground
Board is FR-4 with Er = 4.6.
I have calculated the trace parameters using Saturn PCB design as a "coplanar wave" with a plane below.
I have attached 6 board files showing the actual board (board_image.jpg), rendered board (board_render.png) and the four layers (board_lx.png) + a screenshot of the calculations from Saturn PCB (calc.png). I use the following connectors from Molex:
I have calibrated the VNA in frequency range 2 GHz to 2.8 GHz with the provided SMA cable connected, see attached cal_load.jpg and cal_thru.jpg, direct_load.png, direct_thru.png
Now I connect the PCB trace and do a S11 and S21 measurement (see s11_s21.jpg). It seems to me that the result is not particularly good (see trace_thru.png and trace_load.png).
Can any of you spot any issues with the measurement method or configuration of the board? Also, if you can provide some realistic target results for such a configuration (two connectors + 82 mm trace) that would be great.
Any help is highly appreciated.
Thanks
br
Christian
|
Hi
I have a NanoVNA V2 Plus4.
I am trying to validate a PCB 50 ohm transmission line (trace) to be used for 2.4 GHz Wifi.
I am using a 4 layer stack-up (1.6 mm total) with the following configuration:
L1: Signal + ground pour
Prepreg 0.21 mm
L2: Ground
Prepreg 1 mm
L3: Empty
Prepreg 0.21 mm
L4: Ground
Board is FR-4 with Er = 4.6.
I have calculated the trace parameters using Saturn PCB design as a "coplanar wave" with a plane below.
I have attached 6 board files showing the actual board (board_image.jpg), rendered board (board_render.png) and the four layers (board_lx.png) + a screenshot of the calculations from Saturn PCB (calc.png). I use the following connectors from Molex:
I have calibrated the VNA in frequency range 2 GHz to 2.8 GHz with the provided SMA cable connected, see attached cal_load.jpg and cal_thru.jpg, direct_load.png, direct_thru.png
Now I connect the PCB trace and do a S11 and S21 measurement (see s11_s21.jpg). It seems to me that the result is not particularly good (see trace_thru.png and trace_load.png).
Can any of you spot any issues with the measurement method or configuration of the board? Also, if you can provide some realistic target results for such a configuration (two connectors + 82 mm trace) that would be great.
Any help is highly appreciated.
Thanks
br
Christian
|
For all those slide rule fans out there. Check out this website:
|
Ok, folks, let¡¯s take the slide rule discussion offline, even though it¡¯s very interesting. I have a Pickett C18-T made for Collins Radio, amongst other slide rules and enjoy yakking about them. But this group is about the nanovna. There is, in fact at least one other group dedicated to slide rules.
DaveD
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On Jul 27, 2022, at 08:03, Donald S Brant Jr <dsbrantjr@...> wrote:
?I have a Dietzgen rule with "folded" C and D scales which enable reading to 4 decimal places and specialized scales for solving triangles. I also have several circular rules, including some specialized ones for aviation complete with WWII QA stamps, and my favorite, a "Nuclear Bomb Effects Computer, Revised Edition"; In the movie, this was used by Dr. Strangelove to calculate the half-life of "Cobalt-Thorium G" after it was apparent that the "Doomsday Device" was going to be triggered.
73, Don N2VGU
|
Upgrading to version 0.4.0 fixed this. On connect nvna-s now sets scan range to that set in the device.
|
Photos of my Curta calculator in my left hand¡
|
My favorite slide rule precision story:
Student doing slide rule on a timed quiz and needs to multiply 2X3. He mumbles, ¡°Two times three is 5.999. Oh Hell, call it six!¡±
Larry
AC9OX
|
Hi Joe
Well, typically a dipole at resonance is near 70 Ohms (Resistive), and needs help in some form to get to 50 Ohms.
Making the dipole longer, or shorter, Is moving around those complex impedances.?
So the idea is to experimentally find a length where the Resistive and Complex combine to 50 Ohms or so.? Anything to make that SWR Meter happy!?
The classic figure '8' pattern stays the same from near zero length to about 3/4th wavelength where it starts to become a 4 leaf clover pattern.?? Between near zero and about 3/4ths wave the field strength will vary, but not the '8' pattern.
?Kent
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On Wednesday, July 27, 2022 at 05:31:43 AM CDT, Joe <k1ike_mail@...> wrote: On 7/26/2022 9:05 PM, Jim Lux wrote: But yeah, if you're throwing a dipole for 40m up in a tree,
measurement to the nearest inch/cm is probably good enough. This brings me to a thought that I have had for many years.? Just to nit pick a bit more for science, I hear people say that they "cut the dipole to 50 ohm resonance" when in actuality I believe that they are cutting the dipole to an impedance match.? I've never taken the time to model the antenna in software (on my bucket list to learn this skill) but I really wonder what that does to the radiation pattern.? Probably insignificant on HF frequencies but it would be interesting to put a measurement on the difference. 73, Joe, K1ike
|
OK, how many of you had a Curta calculator? It looked like a black soup can with a crank on the top. You would set numbers on dials and crank the crank until the display stopped changing. That was your result. You could do addition, subtraction, multiplication and division with it. A friend of mine worked in an engineering supply store. He said engineers were always getting curious how the things worked and tried taking them apart. There were spring-loaded parts inside that required a special compression tool. They could never put them back together themselves. His company charged ALMOST as much as a new one to put them back together. Those who took them apart learned never to do it again. Ah, the good ole days! Zack W9SZ <> Virus-free. www.avast.com <> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Wed, Jul 27, 2022 at 7:03 AM Donald S Brant Jr <dsbrantjr@...> wrote: I have a Dietzgen rule with "folded" C and D scales which enable reading
to 4 decimal places and specialized scales for solving triangles. I also
have several circular rules, including some specialized ones for aviation
complete with WWII QA stamps, and my favorite, a "Nuclear Bomb Effects
Computer, Revised Edition";
In the movie, this was used by Dr. Strangelove to calculate the half-life
of "Cobalt-Thorium G" after it was apparent that the "Doomsday Device" was
going to be triggered.
73, Don N2VGU
|
I have a Dietzgen rule with "folded" C and D scales which enable reading to 4 decimal places and specialized scales for solving triangles. I also have several circular rules, including some specialized ones for aviation complete with WWII QA stamps, and my favorite, a "Nuclear Bomb Effects Computer, Revised Edition"; In the movie, this was used by Dr. Strangelove to calculate the half-life of "Cobalt-Thorium G" after it was apparent that the "Doomsday Device" was going to be triggered.
73, Don N2VGU
|
Douglas Butler
Donald S Brant Jr
Stephen W9SK
Glen Jenkins WB4KTF
Martin Glazer
Larry McElhiney