The only AX adapter that can be added to a computer is the Intel AX200. It's an M.2 card and supports monitor mode.
You can use any adapter that supports monitor mode to capture HE management packets. The only thing you need an AX adapter for is to capture HE_MU data packets to explore OFDMA.
If all the parameters you are interested in are in the Beacon, you don't need an AX card. Have you tried sniffing with the adapter you have?
I've attached the Wireshark filter buttons I use, to save you time. Remove the .txt from the filename and put it in your account .config/Wireshark folder.
I don't know of any external M.2 adapters, only PCIe to M.2. You should not have to worry about adapter whitelists if you're running Ubuntu. But if drivers are required for the M.2 adapter, you'll need to see if those are available on Linux. Make sure you get a PCIe to M.2 adapter that supports a wireless card. Many just support SSDs.
The only AX adapter that can be added to a computer is the Intel AX200.
I would think there is still enough of a notebook/laptop market to support more than one card vendor. Apparently not. Broadcom has said it will not produce an M.2 format AX card. Qualcomm has one, but I haven't seen it in the wild. You'd think Mediatek would go after this, but haven't seen them yet.Sad truth. AX is here to speed up our... phones.
Welcome To SNBForums
SNBForums is a community for anyone who wants to learn about or discuss the latest in wireless routers, network storage and the ins and outs of building and maintaining a small network.
If you'd like to post a question, simply register and have at it!
While you're at it, please check out SmallNetBuilder for product reviews and our famous Router Charts, Ranker and plenty more!