USB isolator suggestions?

Jim Lux Всі повідомлення цього користувача #38868 One reason might be that a USB optical link (which is hard to find, FWIW) doesn’t require “opening up the NanoVNA”. (Or a USB/WiFi) In some situations, being able to “plug and play” without needing to get out the soldering iron is an advantage. переключити цитоване повідомлення Показати цитований текст On Dec 7, 2024, at 10:16, Dragan Milivojevic via groups.io <d.milivojevic@...> wrote: There are plenty of serial to BT or WiFi modules available that work with NanoVNA practically out of the box. Why do people insist on reinventing the wheel? On Sat, 7 Dec 2024 at 14:39, Manfred Mornhinweg via groups.io <manfred@...> wrote: I would like to emphasize on the point Jim made: As long as you have an USB cable running into the antenna's near field, it will affect the measurement, even if an USB isolator or an RF isolation transformer is used. Also any isolator or transformer has capacitance, and even if it's just a few pF, this might be enough to cause an unacceptable measurement error in some cases. So I think that the best thing to do is to connect the NanoVNA directly to the antenna, powered by its battery, and use any small battery-powered device to translate between USB and a fiber optic cable. Then run that fiber cable down outside the near field of the antenna, and interface it to the readout software. As an alternative a radio link could be used. On Wifi or similar. If suitable low-cost converters can't be found, it should be simple enough to write a program for an Arduino, to convert between USB and fiber, or use an ESP32 with its built-in WiFi. In fact, given how easy it is to use WiFi with the ESP32, it looks like the way to go! With an ESP32 plus battery attached to the NanoVNA, there is just the capacitance of this small pack to the surroundings, and that should be really negligible on HF. But on VHF and higher even this is enough to significantly affect the measurements. Manfred
Stan Dye Всі повідомлення цього користувача #38869 On Sat, Dec 7, 2024 at 10:45 AM, Jim Lux wrote: doesn’t require “opening up the NanoVNA” The WiFi solution I use doesn't require "opening up the NanoVNA". It's portable and completely wireless. Just a simple short OTG cable between the NanoVNA and an old cell phone (I use an old Samsung S6 without a SIM). I sometimes hold them together with a rubber band, since I haven't tried to make a case. The phone connects to my home WiFi (or I can do a direct WiFi connection to my computer), and I am all set with NanoVNA-app or NanoVNA-saver to use it remotely. Stan KC7XE
Arek Всі повідомлення цього користувача #38870 On 07/12/2024 19:19, W0LEV via groups.io wrote: QUOTE (from Dragen): Why do people insist on reinventing the wheel? WHY: Because they don't take the time to use the search engines. They're lazy and just want someone else to put out the small required effort. I just did search this group archive and also google and the topic is not easy: - what bt module works and fits nanovna case - what module configuration - what firmware - does bt module affect measurements or can it kill inputs - how to connect it / nanovna enclosure placement - what are the other potential problems Is far from "small effort". There are small pieces of information scattered around that you need to find, analyse, figure out which make sense and which not and so on... And groups / mailing lists exist exactly for sharing experience. Especially sharing "solved and tested cases" to avoid having to reinvent the wheel. Dave - WØLEV -- Arkadiusz Miśkiewicz, arekm / ( maven.pl \| pld-linux.org )
Dragan Milivojevic Всі повідомлення цього користувача #38871 You have just proven his point, how do you think that the rest of us figured this one out? We bought the module and played with it. Anyway get this: https://www.aliexpress.com/item/4001035772795.html (HC-05 version). Get some right angle pins and solder them to the board, file a small cutout in the case, make a cable to connect the module. That is it. Every other question that you have you can answer it yourself by using it. On Sun, 8 Dec 2024 at 03:09, Arek via groups.io <arekm@...> wrote: On 07/12/2024 19:19, W0LEV via groups.io wrote: QUOTE (from Dragen): Why do people insist on reinventing the wheel? WHY: Because they don't take the time to use the search engines. They're lazy and just want someone else to put out the small required effort. I just did search this group archive and also google and the topic is not easy: - what bt module works and fits nanovna case - what module configuration - what firmware - does bt module affect measurements or can it kill inputs - how to connect it / nanovna enclosure placement - what are the other potential problems Is far from "small effort". There are small pieces of information scattered around that you need to find, analyse, figure out which make sense and which not and so on... And groups / mailing lists exist exactly for sharing experience. Especially sharing "solved and tested cases" to avoid having to reinvent the wheel. Dave - WØLEV -- Arkadiusz Miśkiewicz, arekm / ( maven.pl \| pld-linux.org )
Manfred Mornhinweg Всі повідомлення цього користувача #38872 Why do people insist on reinventing the wheel? Because it's much more fun than using the same old wheel every time!

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