Work on upgrading the Gawler South node began today with an upgrade of the mast.
The mast, which has both TV and Air Stream equipment on it (even if it's only a bullet), was found to be quite unstable and unsuitable for present and future use. The existing TV antenna mast was a simple corner brace and was literally wired to the chimney! (Wire was wrapped tightly around the stack and that was it!) The amount of wobble that a slight breeze could produce was astonishing.
The new mast (about 6.5m of 50mm galv, 3.4mm wall) is mounted with 50x50x3mm angle bar welded into a U-brace. This is fixed to the chimney with 7 10mm dynabolts. The mast has been designed to tilt down for maintenance by removing the 2 lower bolts, and pivoting it on the top bolt (3x 10mm bolts have been used). As it is without the guide wires is at least 10 times more stable than the original.
All that's left to do is to put in the guide wires and come back later for stage 2 which will be connecting my node into the network. The guide wires will be 5mm 7x7 wire rope with 5mm thimbles, 8mm "D" shackles, and 10mm turnbuckles all sourced from my current work place at Nobles. Similar guide wires were used at the Ottoway install.
The mast at the end of day 1. It's about 3 times the height of the original (for those comparing to my old pictures).
Nekron inspects the mast after the trial erection.
[Edit 16th June, 2010]
Day 2 photos
The mast with it's guide wires.
The mounting bracket. Note the top bolt acts as a pivot.
