In my last post I talked about the middle point of my link having to be a repeater. It also doesn't have any power to this location so I calculated out my power requirments and tower requirments and have gotten to work. I priced some pre-made truss towers and found them to be very expensive.
I looked into doing a 50mm pole with guy-wires but the base would have needed to be 6 meters square.
I decided to make my own truss tower. I ordered some 50mm heavy walled black pipe, and sourced some pre made 12mm solid pre bent webbing.
My TODO list:
Going to need a tower, anything under 8 meters in my area doesn't require a permit. Actually putting in something around 8 meters is going to be a bit of a struggle without a crane, so need to think a little smaller. 50mm black pipe comes in 6.5 metre lengths.
6.5 - minimum depth to support X length tower.
This calculates out to putting at least 1 metre into solid concrete.
I will design the tower to be 5.3 meters in height, allowing 1.2 meters in the ground.
Concrete requirements will be a minimum of 900x900x1200mm which is around 0.972 of a cubic meter. I will flared out the bottom of the hole so I'll work to making up 1.1-1.2 cubic meters of concrete.
Can't get a cement mixer up the hill it's too steep, so this will have to be a manual job. sigh
1 x PTP (point-to-point) antenna.
2 x 120 degree MIMO antenna's (with the option for a 3rd to cover full 360 if needed).
Solar panel(s), batteries, mppt charge controller, small switch to connect the radio gear, something that supports IEEE802.1Q (vlan), would like to go a small managed switch with minimal power requirments.
Circuit breakers to ensure everything plays nice.
Shielded CAT6 cabling, lighting protection and earthing equipment.
The tower is after all sitting up on the ridge line of a hill.
Steel frames to hold the solar panel(s) and a box to put the batteries and gear in.
I like the Ubiquiti equipment and have heard good things about the equipment.
For connectivity from the base station to the repeater tower link I have chosen the "Ubiquiti NanoBeam M5-19 NBE-M5-19" to go at each end. On the repeater tower I have chosen to use 2 x "Ubiquiti airMAX 5GHz 19dBi AM-5G19-120" antenna using the "Ubiquiti Rocket M5 802.11a/n 500mW" radio's.
Powering the devices:
After much reserach I picked out an MPPT controller from ebay. I had heard of several people being burn't buying an mppt controller from ebay only to find it's a cheap pwm knock off. Once I sourced the one I wanted I requested some images of the circuit boards and ensured I was getting the right controller. I ended up going with an i-Panda (yeah I know a chinese one) it's a 12/24/48V 30A charge controller.
For the solar panels I sourced some 2 x JA Solar (JAP6-60-260/3BB) 260W Solar panels. The batteries I have chosen are 125AH 12V AGM Deep Cycle. I have gone with 2 of them to either run the system at 24V or go with 12V I will test once it's up and running which way I will configure it.
So the above covers the power generation and power storage. The MPPT controller will output 12V (for my initial testing) but can be switched to 24V if I need too.