开云体育

Sometimes the 'scale' function needs to be reset to 1:1.
Bob

From: Robert E. Gross

Where can I get better manual or instructions?
==========================



David
--
SatSignal Software - Quality software for you
Web:
Email: david-taylor@...
Twitter: @gm8arv

Your Smith chart 8.png of test field 8 (470 nH) shows at low frequency an
Open.
That can not be correct.

This is correct. 8 contains a series capacitor. This is an isolator at low frequency.

Quite right, whatever impedance but no signal in on CH1 will show 50 ohm. Thanks.
/Torbjorn

Yes. The other ones are OK.

Hugen - Nice work. I am looking forward to working with the improved version.

On the alibaba page, the four inch model is the more expensive of the two listed, correct?

Cheers, bill

50 ohm on CH1 means no input signal to CH1 as expected

--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK

Colin,

What You see in blue on the screen is the CH1 Smith Chart and the value off 50 ohm is to best of my knowledge the input impedance of CH1. Switch to Channel 0 reflect and the marker will jump to the right sida showing infinity. I just tested that myself since I was curious of the 50 ohm on an open CH1. Calibration with SOL on CH0 will not affect what You see on CH1.
Regards/Torbjorn

Hi Hugen,

True, it was sold as an original with the latest software. I soon realized that this was unfortunately not entirely true :-(
This was before I discovered this forum and read that there were a lot of clones…

Thank you all for your response. I will, as Hugen advises, first try to update the software.

From

Quote.....

"NanoVNA is a very compact and portable vector network analyzer created by Mr. TAKAHASHI Tomohiro(edy555), which cost is very low. It is easy to manufacture and provide good measurement accuracy. Mr. Takahashi uses the GPL protocol to open source the NanoVNA software, aiming to attract more young people to pay attention to radio frequency and wireless. Based on Mr. Takahashi's software, I made simple modification to make it measure with odd harmonic. What's more, I have made a version that can measure 900MHz and shared it in the community, which has received widespread attention from the community. Later on, I started to mass produce NanoVNA. At the suggestion of Mr. Takahashi, I renamed my version NanoVNA-H. The community began to contribute new code for NanoVNA, new features were added, cho45 added TDR and screenshot functions to NanoVNA, and QRP73 helped to improve the driver of Si5351 and AIC3204. With more functional requirements being raised, the resources of STM32F072CBT6 are not enough, therefore, under a discussion with Mr. Liao(AA6KL) at /, he proposed the idea to replace STM32F303CCT6 with STM32F072CBT6. I provided Mr. Liao a NanoVNA-H test version with STM32F303CCT6. Thanks to Mr. Takahashi's early work, the porting was smooth. Because the STM32F303CCT6 has a faster SPI bus speed, we started to consider the display size problem which is widely complained by the community. After some selection and testing, we finally used a 4-inch LCD screen.

After discussion with Issues # # 14, we have now increased the measurement frequency of NanoVNA to 1.5GHz. With the larger screen, we have more PCB space for components and batteries. Therefore, we use a separate charge pump to power the mixer and add tantalum capacitors, which can further reduce power supply noise, and the 1950mAh battery can be used independently for more than 8 hours. We add DC dimming to the 4.0 inch full-view LCD screen, which make the view more clearly when used outdoors and more comfortable when used indoors.

In order to make it easier for geeks to create more possibilities, UART1, PC14, and PC15 are introduced on the PCB. Thanks to the manufacturing experience of NanoVNA-H, we made a new ABS shell for NanoVNA-H 4, which can effectively protect SMA connectors and switchs. Each set of NanoVNA-H 4 sold to the community is installed with a complete ABS shell. It is packed in a beautiful gift box, which can surely protect the NanoVNA-H 4 without being damaged during the long-distance express transportation. NanoVNA-H 4 maintains high degree of software compatibility with previous versions of NanoVNA. All software developed for NanoVNA can be used directly. Just note that with the larger LCD screen, the data returned by the “capture” command is twice as long as the original one, but the developers can easily modify the code for compatibility.

I'm selling the full NanoVNA at gen111.taobao.com, if you are an overseas user, you can purchase the hardware I made through alibaba. If you need to trade with PayPal, please contact Maggie through Alibaba. you can also design your own PCB by reference schematic, it should be noted that analog circuit partial shielding and isolation are important, the bridge part is strictly matched, if you need to use harmonic extension 300M or more measurements need to pay special attention."

I have also seen this. Bad calibration kit.
In my case the 50 ohm load did not connect well to the nut ring, which caused bad calibration.
Order a new one in good quality.

Best
Soren

You can measure a filter without a tracking generator and do want you desire... of course WHY. In any case, sure.

Set your generator to the same level as your vna. Stop the vna sweep so you can do this. Then run the generator direct to the SA. That is your zero reference and then insert filter under test. The measure is now IL and same as magS21.

On Fri, Jan 10, 2020 at 08:54 AM, ejfelix4976 wrote:

Just curious, is there a way to calibrate the output amplitude so that when measuring say a filter I can get it to read the same as a calibrated spectrum analyzer??
===============================================

Ed,
When measuring a filter with a spectrum analyzer the usual procedure is to do so in concert with a tracking generator. The S21 (thru measurement) on the NanoVNA accomplishes the same thing within the limits of its dynamic range.

- Herb

On Fri, Jan 10, 2020 at 08:42 AM, Ken Liao, AA6KL wrote:

" Kudos to Takahashi san for his innovative NanoVNA design and willing to share, to Hugen for his meticulous effort to drive down the cost and improve performance, and to everyone for your supports and suggestions. "

==========================================

Ken,
Thanks for the comprehensive rundown of the additional features. Also, don't forget to take a bow yourself for spearheading the larger screen size effort. As a fellow enthusiast, I will be following your involvement in this and whatever other projects you plan in the future.

- Herb

Hi everyone,
Just curious, is there a way to calibrate the output amplitude so that when measuring say a filter I can get it to read the same as a calibrated spectrum analyzer??
Thanks,
Ed

I am glad that Hugen finally decides to release the NanoVNA H4 product, based on F303 and 4" LCD. He kept improving the design that I didn't know when he would be satisfied. Besides these two main features, there are some other improvements.

- RF front-end circuit on noise and sensitivity improvement.
- Power management circuit.
- Larger battery capacity.
- UART and two other GPIO pins are brought out to allow for Bluetooth, BLE, or any other connections.
- Jog switch sensitivity.
- Enter DFU by pressing down the jog switch at power-on. The LCD screen will be black at DFU mode. We have to do so since the software jump to DFU mode doesn't work for F303.

Initially, I was thinking of using NanoVNA to learn ChibiOS, but I disliked the flash size of STM32F072. So I contacted Hugen to discuss the possibility of replacing F072 with larger MCU, and invited him to join this forum. Here, Hugen received lots of feedback from the community. So he decided to make the F303 based NanoVNA with larger LCD. We contacted the NanoVNA's original author Takahashi san (edy555), who is an enthusiast in promoting RF engineering. He gave Hugen some advices. Currently he is planning a new project. Maybe it's another VNA covering higher frequency and better sensitivity, or maybe another useful tool. We will know soon.

For this project, I worked on the software porting to F303, used ChibiOS's ADC API for touchscreen, and ported the LCD display controller to ST7796S to support 320x480 4" LCD. Hugen carefully verified my codes and fixed some GUI issue and used larger fonts. He also incorporated some improvements and suggestions from GitHub users, including edy555, cho45, qrp73, Pmax65, etc.

The NanoVNA-H4 and NanoVNA-F took different approaches to provide larger screen. NanoVNA-F is an excellent product with larger, bright and high resolution LCD, larger battery, metal case, and is FreeRTOS based; while Hugen and I think that keep price low and continue to use software based on original NanoVNA code could better promote community involvement.

There are still places to be improved, such as the touchscreen responsiveness. Hugen and I will post firmwareupdate if we have any fix.

Kudos to Takahashi san for his innovative NanoVNA design and willing to share, to Hugen for his meticulous effort to drive down the cost and improve performance, and to everyone for your supports and suggestions.

73
Ken Liao, AA6KL

On Fri, Jan 10, 2020 at 08:37 AM, Dick wrote:

Is this model the one with the Big screen or the Little screen ?
=======================================

Dick,
Current model has 2.8" screen. This model has 4" LCD. See previous messages for other differences (larger battery, etc.).

- Herb

Is this model the one with the Big screen or the Little screen ?

Thanks, Dick, W1KSZ
________________________________
From: [email protected] <[email protected]> on behalf of hwalker <herbwalker2476@...>
Sent: Friday, January 10, 2020 9:27 AM
To: [email protected] <[email protected]>
Subject: Re: [nanovna-users] We started selling nanoVNA-H4 using STM32F303CCT6 and 4-inch LCD

When I try that using Firefox, I get a blank white window after hitting "Send inquiry now" and, yes, I checked the agree with Alibaba box
==============================================

Glen,
On the right hand side of the page there should be an area that allows you to start a chat with Maggie King for Paypal purchases. You generally have to check back for a reply in a few hours after sending your request because of the time zone differences.

- Herb

On Tue, Jan 7, 2020 at 02:26 AM, Gabriel Tenma White wrote:

Because of popular demand we replaced the jog switch with buttons
=====================================================

Gabriel,
Have you noticed any detuning effects from hand capacitance by having the buttons in such close proximity to the connectors? The selection of buttons over the jog switch should make the unit more durable, especially for heavy handed users.

Happy to see that you have added the python branch to your GitHub repository.

- Herb