Tiny/Mini/Micro WiFi not Recognizing Available Networks

[ragnar01]

Not sure this is the right place to post but...

To add some physical test clients to my homelab I picked up an Optiplex3050Tiny (7500T) and a Thinkcentre910QMicro (7500T) - no wifi chips.

When I install an M.2 9260N or AX210 to either one, the wifi chips are physically recognized during Win10 install but they do not see the various wifi SSID visible in the basement. I can see the WiFi adapter and drivers are loaded (and activated) but they never pick up any of the normal SSIDs. They will usually show 1 (unknown) hidden network only. If I install Windows with (or even just plug in) a TPLink USB Wifi adapter, it shows up immediately as a 9260N adapter and shows the 20-30 wifi networks in the neighborhood.

I've reinstalled Win10Pro maybe 10 times so far. Maybe....1 or 2 times the scan would show one of the robovacs or smart TVs that have yet/never been networked (??acting as access points??) but this doesn't seem to be consciously reproducible.

Any possible fixes or suggestions where to search - I'm sure this is obvious but the Googles aren't coming up for me.

 

[DavidWJohnston]

Did you install antennas on the M.2 adapter?

If not, they are necessary - Have a look at this:

There are tiny RF connectors, in your case probably IPEX4; the smaller one on the bottom, but double-check:




You can buy the proper cables and antennas from Amazon: Amazon.com : m.2 wifi antenna

If the computer case is metal, the antennas will need to be outside the case for good performance.

 

[ragnar01]

The absolute need for antennas was also suggested in response to my reddit request. Regardless I now have a set of the NGFF antenna leads and antennas on the way from Amazon.

I was/am a little bit skeptical in that I always see the 1 hidden-network and I thought I randomly saw the monitor(TV) and robovac unsecured access points show up (but that could be a false memory (age and all...). I could easily understand a drastically reduced working range or limited visibility of more distant SSIDs from outside the house but NO other networks visible even if the high power access point is <15' away.??? The other thing I can't understand is the lack of similar complaints for the many Amazon M.2 card listings that do not ship with antenna leads - I would have expected more ....complaints.

Tks for the response. I will post/update my results as they become available

 

[DavidWJohnston]

Perfect, that should work for you. RF electronics and ham radio is another hobby of mine so this stuff interests me a lot. If you don't care just ignore this ramble below.

Anything metal (like board traces or screws) can by pure chance act as an antenna and crosstalk to the receiver, albeit very poorly. The resonant bandwidth may be so narrow and weak that it just barely receives on one specific WiFi channel only. So any device transmitting on that channel has a small chance of being seen, and everything else is below the sensitivity of the receiver, even if it's close.

RF engineers try hard to avoid these spurious resonances; in your case it's probably the only reason you received anything at all. Modern WiFi receivers are very sensitive precision devices and will work a bit even in adverse conditions.

Without an antenna, transmit would be inhibited due to a high SWR condition. (Attempting to transmit without an antenna can damage the transmitter, so they shut themselves down under such conditions) So even if you see an SSID you have no chance of connecting to it.

The ultra-tiny high-performance antennas used in phones, and some IoT devices are a relatively recent invention. They use numerical models to "brute force" optimized antenna designs from stated design constraints like size, frequency, radiation pattern, bandwidth, SWR, power handling, etc. When supercomputers/GPUs iterate these equations, you get strange-looking antennas that you wouldn't think would do anything - But sure enough they have superb performance at just the right frequencies. This is especially important when you need an antenna that can transmit in several far-apart bands, like 4G/5G and maintain reasonable battery usage.

People buying M.2 WiFI cards might normally be upgrading an old one, and the antennas are already in-place and the user just re-plugs them into the new board. And who knows, there may be other WiFi-specific reasons some SSIDs show under adverse RF conditions, and some don't. (beam forming, beacon speed, etc)

 

[ragnar01]

Well....that was interesting and humbling - I received the antenna leads with a pair of flexi plastic antennas - snapped them on and voila - wifi networks are now visible. Not as many or nearly as strong as with the TPLink plug in USB adapter but a bunch none the less. ...sigh... my skepticism was definitely unwarranted.

Lesson learned - M.2 wifi cards absolutely need antennas to be at all usable.

WTF questions raised - hardly any of the Amazon/eBay vendors sell the wifi cards with the antennas/leads - Why wouldn't they all at least highlight the need to have both in their ads to reduce unwarranted "It's DOA" returns. I am also surprised that this issue/question hasn't come up a million times already on the Googles - either that or my choice of search terms is far worse than I originally thought.

Thanks again for the response pointing me in the direction of the obvious and simple fix.

 

[DavidWJohnston]

No worries, from others here I learn new things all the time - Some of them simpler than I'd like to admit.