Air-Steam-Athelstone

After 2.5 years of flawless operation using OpenWRT flashed Mitsubishi R100 boards (aka Asus WL500G) the Athelstone access point was upgraded in July 2009 to an all Mikrotik Routerboard affair. The upgrade plan was as follows:

  • Keep current backbone antenna, replace backbone radio with a new Mikrotik Routerboard RB433AH and a new 5GHz card, a Mikrotik R5H (old card - still works perfectly, R5H is just better)
  • Upgrade Valley View side of the backbone with a new, better, wireless card
  • Replace omni radio with a dedicated Mikrotik Routerboard RB411A and a new Ubiquiti XR2 card (old card SR2 - a bit flakey)
  • Extend the mast with a 1.5 meter "omni-extension"
  • Replace cheap and nasty omni with a proper Superpass 8dBi omni antenna mounted at the very top of the new omni extension
  • Move backbone antenna as high as possible on the original mast
  • Refresh main guy wires, turnbuckles and wire grips
  • New Cat5e cabling throughout with passive PoE (old system - dedicated 5V wiring)
  • New high performance LMR100 pigtails for all cards
  • New LMR195 short run coax cabling for all antennas
  • All new DIY battery backed 24V power system, individual circuits and Cat5e runs for each board
  • New weatherproof enclosures for both boards
  • Weatherproof screw-on/screw-off RJ45 feedthrough for easy removal of RB433AH enclosure

Pictures from the dismantling of Athelstone Mk1


The old 'biscuit tin' enclosure


Cheap and nasty omni with rusted mounts

Pictures from the construction


RB433AH enclosure, a modified Die-cast Aluminium enclosure (HB5050) with a spare antenna hole drilled for future growth


RB411A mounted on backplate


RB411A enclosure, a modified polycarbonate enclosure (HB6218) with backplate and ground wire that will be connected to the mast


RB411A test fit on backplate inside its enclosure

Pictures from the install


Omni extension completed


Superpass omni mounting arrangement


Mast completed


Backbone antenna and enclosure


New mast going up


Power control center. Uses a solar regulator and some SLA batteries to provide a UPS but instead of using solar panels it is fed by a 60W Switchmode 24V PSU. Individual fuses for each PoE circuit after the regulator, and an overall fuse before the regulator. The 24V DC PSU is mounted inside another HB5050 with a 24V fan providing cooling, a maintainable air filter and 240V IEC socket. The PSU has its own fuse protection.


Update: Even though the boards were tested before raising the mast, when the omni board was turned on for the first time after the mast being raised it was dead. We needed to replace the wireless card....in situ.

Conclusion

Thanks to DrGeforce3 and rativiv for their hard work in helping to make this upgrade go to plan. The new Routerboard system provided a significant throughput improvement thanks to the RouterOS NStream enhancements. The omni can now 'pick up' much more wireless junk than before when doing a scan so I suppose this means that the height and improvement in antenna quality has helped. We have had a successful client connect to the omni from Modbury North at a distance of 7.1km. Overall the whole setup is a huge improvement in the quality of the access point and will ensure that it remains strong for many years.

With lessons learned from previous experience and errors we have upgraded the following facilities, a) The omni is now as high as practically possible to give better coverage as the old omni was not used as much as we had hoped, b) The power system is now very robust, the previous system blew 3 power supplies, c) The RB433AH enclosure is ready-to-upgrade without any further drilling - an annoying and time consuming process having to remove all electronics to make another hole, d) The RB433AH Ethernet cable can be removed from the outside, allowing quicker and safer removal of the entire enclosure off the mast without having to unscrew lids in mid-air - again easier upgrades and repairs, e) Mast real-estate usage is minimised for best antenna placement and allowance for growth.