[xmddmx]

In the USA, there is one non-DFS 5GHz channel which is somewhat unique: Channel 165. It's limited to 20MHz bandwidth, and if you google it you will see warnings against using it.

On the other hand, since nobody uses it, it's generally totally clear, and if your AP and client devices support it (and you can live with the lower bandwidth) it can be a nice "secret" channel to use in a noisy 5GHz environment.

[spmurrayzzz]

This is the most practical advice I tend to give folks, even if its a bit niche.

Not everyone has a spectrum analyzer of course to verify this, but if you have a reasonable assurance that the channel is not being used and your devices are AC/AX that can make use of at least 2+ spatial streams, that more than makes up for the truncated channel width in most cases.

[digitallyfree]

Ah, I love 165. I've never seen it utilized even in downtown areas and I generally recommend it if you are in a congested area and are fine with the performance on 20MHz.