As of 2023 there are many badly performing clones on the market. V2/3GHz NanoVNA uses parts like ADF4350 and AD8342 which are costly and clones have been cutting costs by using salvaged or reject parts.
See official store and look for V2 Plus4/V2 Plus4 Pro versions only to avoid getting a bad clone. We have stopped selling V2.2 versions since October 2020, so all V2 hardware that are not Plus or Plus4 are not made by us and we can not guarantee performance.
After two years of use my Amazon clone AURSINC SAA-2N Will not Calibrate properly. SOLT calibration no longer a nice ti tight point on the Smith chart, it dances all over. Open is the worst it will drift significantly across Smith chart after calibration. Time for the trash, or replaceable component?
Have you looked for cold solder joints on the SMA connectors? It could be they were damages in “normal” use since they are the weak point
Frank
KA2FWC
Hello, I also had a similar error., after 2 years.
There are errors in the measurements and the green arc-shaped curve that moves from left to right at the opening is very small and remains in the middle. Previously, the green curve opened from the left and spread to the right.
This problem occurred after I touched the soldering iron tip when VNA was connected to the charger.
while I was testing a circuit measurements.
I'm thinking of reinstalling the firmware.
Can U sent me a photo ur VNA after switch on
kadrimehmet@gmail.com
73
TA1D Kadri
Be aware that soldering irons can develop current leakage that can destroy
sensitive components. On production lines, we would periodically check
soldering irons with an oscilloscope and scrap the bad ones.
On Sat, Dec 9, 2023 at 10:29 AM TA1D - kadri <kadrimehmet@gmail.com> wrote:
Also worth checking the sma connector face and cal standards are clean. Use a cotton bud and IPA.
The center pin on the sma standards is fixed to the body, so when you twist it on the pin rotates in the socket and over time this wears and creates metal dust that sticks to the face of the socket. You then get increased coupling to ground. I remember seeing a paper on this but can't find it.
Most sma plugs allow you to keep the center pin and cable assembly stationary while you rotate the threaded part. This is how you're meant to attach them but many don't and with the cal standards provided it's not possible.
Another good reason to connect the supplied cables and never take them off.
Labs often use SMA connector savers. M on one side and F on the other.
Placed on the instrument and rarely removed.
On Sun, Dec 10, 2023 at 10:29 AM RadioUser via groups.io <benjaminq=
gmx.com@groups.io> wrote:
Too late, :( I reloaded firmware, same issue, Disassembled removed LCD board, reheated solder joints around SMA connectors, reassembled, same bad behavior. Found pressure on s11 n connector made trace jump like crazy. disassembled again, could not figure out how to remove tin shielding box over that connection without destroying the pcb. I went to Hamfest Friday foun 2 SAA 2N Nanos also not working, same unstable trace after calibration. Found a Nano VNA H for $20 that worked, bought it. I came home said goodbye to the SAA 2N and tossed it. it did serve me well for two years.
Hi, you may ask the seller for warranty service. We generally will do repairs free of charge, but on genuine units only. You can check https://nanorfe.com/nanovna-v2.html for where to find an original unit next time to be sure you will get a unit that is covered by warranty. If you unknowingly received a clone, you should ask for a refund on the platform you bought it from. Thanks
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