I remember seeing a poll question asking about 3.3 Ghz mesh net nodes. I did a quick search on this site and came up empty. So, either I did not use an appropriate search term or it is an unexplored area.

So, is there any development on using the Ubiquity 3.3 Ghz equipment as Broadband Hamnet nodes? (Rocket M @ 3/3.6 Ghz listing as an example)

You are correct. I have looked into this for a considerable time. To summarize, UBNT 3.4GHz radios are merely UBNT 5GHz devices with a 2GHz downconverter. The 3.4GHz US hamband (before downconverting) falls between the 5GHz "Lower Band" (5150-5320MHz) and the 5GHz "Middle Band" (5500-5850MHz). The PA on the M3 devices are rated from 3.5GHz to 3.7GHz Furthermore, the output power drops off considerably outside the PA's range. So much so that the devices do not even see eachother on 5320MHz even when they are touching with the antennas pointed directly at each other. Simply put, it is not easy, but I am sure we will get there eventually.

Actually interesting you bring this up.

After the 3.0.0 release went RTW I spent a week and a half feeling my way around the build root, investigating various items and overall improving my general knowledge so I can better prepare for the next version iteration. 

With 900MHz out the door were now into the deeper more in depth hardware models that require a deeper understanding of hardware (which the past year with Ubiquiti gear has helped us gain that knowledge)

The 365 model testing has shown to have frontend filtering that sharply rolls off rendering them unusable for Part 97 usage. Since he focus is Part 97 (or world equivalent) not much additional focus was put towards the 365 units.

The M3 is an interesting unit as Paul explains .  It is a 5GHz node with a downconverter inside. This at first is a good thing, it means minimal changes to the rest of the system.  The interesting part comes with the fact that the drivers we use do not intended to go in to a middle dead band between two of the part 15 bands.  This is similar to the channel 0 issue for 2.4 GHz discussed elsewhere.  The advantage to the M3 is it's expected to operate in that band, I expect we will find additional calibration data that we can work on pulling in.

It has a fair bit of work before it will even be ready for testing but as Paul says in time we will likely pull in the M3 in time. It certainly is on the desire plan as it's a band many may find useful (though I'm not sure I will get to use it as San Diego  may be in an area for DoD 3.4GHz radar more research is needed on that as well) 

We worked the easy gear, now it's on to the advanced topics as the dev team working on Ubiquiti looks to continue to raise the bar on what we can do with these powerful yet affordable devices.

I wouldn't hold your breath on it being "soon" however as the one thing I've learned over the past year is nothing goes as planned. We likely have a large number of hours ahead of us working on this and other priorities that it will take time to produce.  As much as has been learned we still have more.

Conrad, would it be possible to use the ubiquity software at 3G and run the the mesh through a tunnel until the M3 units are supported?

While it should be doable I do not have any instructions on how you would do it.

Ideally you would want to bring up a new interface (say vlan 9 so it's out and away from anything we actively use or may use in the future) and probably set it up with an IP in the VPN address space and add the required routing and firewall rules and dns rules.

The other alternative would be to modify the dtdlink but then you need to remember you made changes if you replace the device and you won't be able to dtdlink to other devices without modifying them as well. 

Hello Conrad. I am not following your line of thought. Are you referring to the use of the "factory" Ubiquiti firmware (airmax) or are you referring to using a modified version of BBHN software?

I presume that you are referring to using the 3Ghz equipment as a "backbone" tunnel for say 2 local BBHN meshs.

Correct using a BBHN node paired with an M3 in factory install until M3's become supported.