I have 8 buildings that need connected at most 800m. Each building will have 3 radios for a ring and spoke setup. I need to deliver 100mb minimum to all buildings from the main building. I have some ideas for the networking, but the wireless is tricky. What would be nice is some highly directional antennas with very low gain ( to cut down on noise). Maybe put 100ft of lmr in the middle. I will probably be using r52n radios. Any ideas?

Sounds like a job for fiber to me. Got any light poles you can attach to instead of trenching?

Try leaky feeder
http://www.solwise.co.uk/wireless-leaky ... -cable.htm

Although I am well versed on leaky feeder through tunnels for bandII fm (vhf) I have no idea how it performs at Microwaves.

Buy, hey, its available.. They have an expert at the link I gave you who will assist in your project.

those leaky feeders are awesome, but I am looking for a ptp antenna that will have good performance at short range and reject interference.

I was thinking of using a high gain dual pole dish with a couple things to drop the overall signal like a lightning arrestor, cavity filter, a few feet of lmr etc. If I could use a 250mw card, 25db dish at 800m, my signal is -50 buy my noise is -93 then drop the signal by 9db, I would still have better than -60 and my noise would drop down to -102 (in theory).

Does this sound like a good Idea? The links I have in this area now I have to drop to 5mhz channels to get a clean signal, so I am lucky to get 15mbit. I have not tested any N yet.

You could try one of these attenuators. They are a lot smaller than 100 feet of cable.

http://www.thetestequipmentstore.com/at ... _level_set