N2201 VNA - Page 1
Forum section: electronics / rf-microwave

author: splin
author_rank: Frequent Contributor
timestamp: November 21, 2018, 01:26:59 am
content: I'm considering buying an N1201 or N2201 after seeing the former on Andreas Spiess's youtube channel. I'm no expert in this area but they look like a good tool for checking Antennae (up to 2.4GHz). I realise that a 50 ohm dummy load would have an excellent VSWR but would be a pretty rubbish antenna, but checking that an antenna has the right resonant frequency has to be a good start.The N2201 can also measure power which is interesting, but I have no idea about the accuracy. It also has 2 ports but I'm not sure of the benefit. The N2201SA is on offer at $173.7 in the Aliexpress Black Friday sale:https://www.aliexpress.com/item/English-verison-N2201SS-n2201-137-5MHZ-to-2-7GHZ-UV-RF-Vector-Impedance-ANT-SWR-Antenna/32954352952.html?spm=2114.search0104.3.1.4eae58bfUkLhwU&ws_ab_test=searchweb0_0,searchweb201602_2_10065_10068_10130_10547_319_10548_317_5733915_10696_10192_10190_10924_453_10084_454_10083_5733715_10618_10920_10921_10922_10307_10820_10301_10821_10303_537_536_5733815_10059_10884_5734015_10887_100031_321_322_10103,searchweb201603_2,ppcSwitch_0&algo_expid=2fdb2abe-4091-49b9-aed3-e523297d3478-0&algo_pvid=2fdb2abe-4091-49b9-aed3-e523297d3478Problem is there seem to be a number of variants and I can't find a definitive description of the differences - eg. N2201SS and N2201SA. Also some vendors add 'English version' to the description. Is this important or do all current versions include English menus?

author: grizewald
author_rank: Frequent Contributor
timestamp: November 21, 2018, 10:14:16 pm
content: You do have to make sure you are buying the English version. These meters come with either a Chinese interface or an English interface and you can't select the language on the device itself.The N2201SS has the two ports. One for making S11 measurements and the other for measuring power. They imply that you can measure S21 on the N2201SS, but do not actually describe how to do this in the manual. The stated accuracy of the power meter is:Code:0dBm - 8dBm +/- 1dBm-10dBm - 0dBm +/- 1.5dBm-20dBm - -10dBm +/- 2dBmThe N1201SA has one port and only provides S11 measurements. It does not have a power meter.I have an N1201SA and it's very good for the money. It will show the complex impedance for whatever point in the frequency frequency span you select. The results are indicative rather than calibrated and the resolution isn't earth shattering, but it does a good job for checking and tuning antennas up to 2.7GHz. I just wish it went up to 6GHz!

author: splin
author_rank: Frequent Contributor
timestamp: November 21, 2018, 11:17:16 pm
content: Thank you - great information.Do you know any website that details all the different models and the minor variants? In particular I can't find out the difference between the N2201SA and the N2201SS.

author: grizewald
author_rank: Frequent Contributor
timestamp: November 22, 2018, 07:24:12 am
content: I don't know of a web site for AAI. I don't think they have one. The only info I could find was the developer's blog:http://blog.sina.com.cn/u/5635362932The 1201 has three different models: SA, SAC and SA+The difference between the SA and SAC versions is that the C version has a data output via USB.The SA+ version extends the SA version's lower frequency limit down to 34.375MHz.I have the manuals for the N1201xx and for the N2201SS, but I can't attach them here as they are too large. If you want to drop me your e-mail, I can send them to you if you want.

author: NW27
author_rank: Regular Contributor
timestamp: April 18, 2019, 11:40:53 am
content: Hi splin,How did you go, did you buy a Nn201 analyser?I'm also interested in one of these and toying with the idea of the N2201.Thanks,Neil.Sent from my SM-N960F using Tapatalk

author: splin
author_rank: Frequent Contributor
timestamp: April 19, 2019, 01:23:10 am
content: Quote from: NW27 on April 18, 2019, 11:40:53 amNo sorry; circumstances changed a bit so I decided to hold off for the time being until I really need it. That and a bit of 'analysis - paralysis' trying to decide which would be the best model to get - ie. procrastination!

author: 0xdeadbeef
author_rank: Super Contributor
timestamp: July 27, 2019, 06:19:26 pm
content: Quote from: grizewald on November 22, 2018, 07:24:12 amAs the SAC and SA+ version are virtually non-existent, I wonder if anybody ever tried to hack an N1201SA into a SA+, SAC or even "SAC+".Regarding the SA+, I would assume that mainly the ADF4350 was replaced with an ADF4351.Regarding the SAC, at least in some (1.6x/1.7x) PCB revisions there is an unpopulated header J4 with RX/TX markings next to the USB charging connector. So I guess there could be some TTL level UART there which could be used to communicate with the device. Newer PCB revisions (2.70) seem to have sacrificed that header for another (USB-C) charging connector though.However, I would assume that the devices also have (slightly?) different firmware and as the devices are not user-upgradable, there are no firmware images floating around. Actually, unlike the nanoVNA or the mini600/1300, these devices seem to originate in China, so there is no source code available. At least I couldn't find any hint. Anyway, there is another unpopulated header called J6, which is obviously the debug port since SWDIO (PA13) and SWCLK (PA14) are connected there. So did someone try if it's possible to read back the flash from there? The CPU should be an STM32F103CB (LQFP64).