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Re: nanovna-saver question
#nanovna-saver
Charlie N2MHS
Mine starts goes to DOS window and then windows window in under 3 seconds.Add some laser oil to your dilithium crystals.....or how much stuff is in your process table
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On Wednesday, July 27, 2022 at 09:59:22 PM EDT, Glen Jenkins WB4KTF <wb4ktf@...> wrote:
I had not waited long enough, it did take a while and did pop up and run successfully. Thanks to all who replied. ----- Glen Jenkins, WB4KTF, Austin, TX |
Re: nanovna-saver question
#nanovna-saver
I had not waited long enough, it did take a while and did pop up and run successfully.
Thanks to all who replied. ----- Glen Jenkins, WB4KTF, Austin, TX |
Re: #measurement
#measurement
On 7/27/22 5:25 PM, Donald S Brant Jr wrote:
At a glance I noticed the wide traces at the connector pins, which are excess capacitance. Unless there is a compelling reason to do otherwise I tend to select a dielectric material whose 50¦¸ width is slightly larger than the connector pins and component pads I plan on using. It is only necessary to use thin boards such as you are using for very high frequency (>20+GHz perhaps), work, to avoid resonances and radiation. 0.8mm board (or thicker) might be more appropriate.As I recall, 50 ohms on 1 ounce copper on an 0.031" board with epsilon=2.5 as microstripline was 0.1" wide. There's countless calculators out there. If you pick the board correctly, a 4 pin SMA solders on very nicely. (the gap between corner pin and center pin is about 1 mm, which is close to 0.039") I also like to pull the solder mask away from the RF traces ideally 2 line widths wide, again to avoid excess capacitance; solder mask has a higher dielectric constant than air. This excess capacitance is particularly problematic in the gaps between RF line and ground of your . |
Re: #measurement
#measurement
ONLY if you test that coupon at 2,400,000,000 Hz!
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Testing with the typical C Meter won't do it!?? The usual standard is 1000 Hz. The Er changes with frequency when you get in the MHz.and up.?? Kent On Wednesday, July 27, 2022 at 07:04:11 PM CDT, Jim Lux <jimlux@...> wrote:
On 7/27/22 9:18 AM, KENT BRITAIN wrote: ? Hi ChristianMost people do a test coupon, which is essentially what you're doing. 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.
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Re: #measurement
#measurement
At a glance I noticed the wide traces at the connector pins, which are excess capacitance. Unless there is a compelling reason to do otherwise I tend to select a dielectric material whose 50¦¸ width is slightly larger than the connector pins and component pads I plan on using. It is only necessary to use thin boards such as you are using for very high frequency (>20+GHz perhaps), work, to avoid resonances and radiation. 0.8mm board (or thicker) might be more appropriate.
I also like to pull the solder mask away from the RF traces ideally 2 line widths wide, again to avoid excess capacitance; solder mask has a higher dielectric constant than air. This excess capacitance is particularly problematic in the gaps between RF line and ground of your . I like to chamfer the corners of the transmission lines and leave a small gap at the connector pin, again to avoid excess capacitance. Finally, many board houses charge per hole drilled ("hits") and if so, you can drastically reduce the number of vias to a single line on each side of the RF line, with a cluster of vias, or better yet, wraparound grounds (could be copper foil added at assembly), for the connector grounds. Best regards, Don Brant. |
Re: nanovna-saver question
#nanovna-saver
Especially the long waiting time is where many users think its not working...
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Yes it takes a loooong while :-) Dg9bfc sigi Am 28.07.2022 00:05 schrieb Stan Dye <standye@...>:
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Re: #measurement
#measurement
On 7/27/22 9:18 AM, KENT BRITAIN wrote:
Hi ChristianMost 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 |
Re: nanovna-saver question
#nanovna-saver
Mark Savage 2E0HXP
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, |
Re: Antennas
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 |
Re: nanovna-saver question
#nanovna-saver
Also, just wait a very long time. It takes saver two or three minutes
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(seems like forever) to load up all the required python stuff, after that command window opens, especially the first time you start. 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. |
Re: nanovna-saver question
#nanovna-saver
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).
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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 |
Re: nanovna-saver question
#nanovna-saver
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 |
Re: Antennas
Hi
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I remember my late Father had a White slide rule. He had. EE from UCLA. he used at work. Martin N6QLh 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 |
Re: #measurement
#measurement
Hi Christian
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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 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 |
#measurement
#measurement
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 ![]()
board_l1.png
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board_L2.png
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trace_load.png
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trace_thru.png
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direct_load.png
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direct_thru.png
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board_l3.png
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board_l4.png
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board_render.png
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board_image.jpg
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calc.png
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cal_load.jpg
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cal_thru.jpg
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s11_s21.jpg
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