It's obviously a point to point transmission, not networking so it wont be bound with such standards like 802.11. But that said, trying to do that without any frequency hopping in such a crowded band is in my opinion very likely to experience some difficulties, and the previous post seems to reference "diversity antennas" which to me suggest that they may be trying to do that, transmit on a single (well 3 since there are three channels) frequency carrier. Hard to know for sure but a pair of diversity antennas is more alike antenna hopping (not exactly but rough idea) instead of frequency and sounds like a weird choice in this band.I did a little bit of search to find the type of "3 selectable Channel" RF (WiFi? 802.11?) communication is being used.
I found out that the referenced "3 channels" may be those 3 that are considered the "non-overlapping (20MHz)" ones (802.11b/g/n @2.4GHz WiFi-band) shown in diagram below…
View attachment 211387
Those same 3-channels are also used by BlueTooth, baby monitors, car alarms sensors, garage doors, MicrowaveOvens, Zigbee/SmartHome devices, etc.
View attachment 211388
Theoretically the 802.11a/n/ac offers 25 such channels of which only 9 are unrestricted (non-DFS) allocation
View attachment 211389
I got nowhere: Even the NAD site lacks any information about the RF technology or type or specs.
The NAD DAC2' FCC certification shows approval for 2.4GHz band but another source alluding to: "The wireless transmission takes place at frequencies of 2.4, 5.2 and 5.8 gigahertz, and you can access the three channels by using the manual switch…"
Not that @amirm' test results showed any disruptions or drop-outs (etc.), but at least one other person talked about line-of-sight obstruction of the wireless signal.
I had an AudioEngine D2 wireless-audio system (using 17-band spread-spectrum in the WiFi (2.4GHz band) which had co-channel interference issues with other neighborhood WiFi activity.
It should not be this difficult but WiFi "6E" (5.925 to 7.125GHz) may even increase the line-of-sight related reception problems.
Now as a more general thought, the FCC filing is obviously more reliable than this other source.