I have a few questions with HAP AC3 antenna specifically, and hope the wireless experts on this forum can assist:
Are the two antennas identical and are used for both 2.4Ghz and 5Ghz?
Similarly, are both antenna connector at the back of AC3 used for both frequencies? Or is one 2.4Ghz and the other 5Ghz? There isn’t any markings for frequency
If I only use 5Ghz for WiFi (with 2.4Ghz disabled), do I still need to plug both antenna into the router?
What’s the pattern of the signals coming off these antennas. Should I be facing the flat side at my devices for best signal?
The two antennae are for MIMO - theoretically doubling the wireless connection throughput.
Pattern is mostly omnidirectional with shape of a torus - lower signal strength in direction along antennae. So you should direct antennae mostly in vertical position and client devices should be more or less on the same level (i.e. signal one floor above AP will be lower than behind a wall on the same floor).
Cannot vouch for the possibility of damage without them attached, but can vouch for the total uselessness of those two antennae on AC3.
All they do is take space without adding any benefits to WiFi signal, noise or coverage, comparing to AC2 or wAP AC.
Maybe there is something Mikrotik needs to upgrade in their firmware, but I doubt it.