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Subject: Re: every other wireless scan shows bogus (too low) signal strengths
To:     Julian Calaby <julian.calaby@gmail.com>
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Cc:     Johannes Berg <johannes@sipsolutions.net>,
        linux-wireless@vger.kernel.org
From:   Bruno Dantas <dantas@airpost.net>
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Date:   Fri, 2 Dec 2022 10:21:44 -0500
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Hi, Julian.

> Stupid question, is there any chance that one of the antennas is damaged?
As best as I can tell, both antennas (black and gray wires) are intact.

> You might get slightly different behaviour if you swap them - if your
> X230 is anything like my X200, there should be enough slack do that.
Good idea, so I gave it a shot. Alas, behavior is the same when I swap the black and gray antennas.

I have a stash of these Intel AC 7265 half-height mini PCIe WiFi adapters, so thought I'd try yet another one. Interestingly, with the third adapter the behavior is worse: Every scan gives me the spuriously low signal strengths. I put my original adapter back in, of course.

Maybe doing a wifi network scan requires more power than just authenticating with an AP and using the network? And maybe my after-market 802.11ac adapter requires a bit more power than the 802.11n adapters that were around when this laptop was made? If so, maybe it takes this old laptop's PCI bus two attempts before the 802.11ac adapter has enough power to do an accurate network scan? That's a lot of maybes, but it's my best guess given the behavior I'm observing.

I'm ready to give up on troubleshooting this (for now, anyway). I can live with my workaround of discarding every other network scan result.

Thank you guys for your help.