Naracoorte antenna working bee

At long last the Naracoorte 2M antenna has been replaced. It was almost a year ago that we discovered that the SWR on the 2M antenna was 2:1. Almost certainly one half of the system was broken away or corrosion had affected the system.

Late in 2019 the Naracoorte Club (NARC) agreed to pay for a new commercial  antenna and this was purchased and tested at VK5BE’s shack. It worked fine and was then disassembled and prepared for installation on a length of aluminium scaffolding purchased by SERG.

Finally the big days arrived with two possible dates for the crane, 13 or 20 March 2020. Winds were high on the 13th so the crane was booked for the 20th. The crane arrived on site at 9:00AM. The cost of the crane will be paid by SERG, safety was the prime consideration.

After checking the coax was fine by placing a dummy load at the top of the coax and testing for SWR from the bottom, the working bee began in earnest. Norbert VK5MQ was in charge and worked in the basket with the rigger.

By 10:45AM the pole was in place but winds had become too high to work safely so it was decided to call it off until 3:00PM in the afternoon.

Work continued at 3:00PM. By 5:00PM work was completed.

The antenna was tested from ground level with an immeasurable return loss and the repeater was put back on air. The LimeFM FM transmitter was also put back on air. LimeFM rent some tower space from the Naracoorte Club and their two folded dipoles can be seen lower on the tower and a 3 element Yagi for their link from the Bluff.

Here are some photos of the action taken by Peter VK5BE.

Ready for the dismantle, the 4 old dipoles can be seen at top, below these the 3 element yagi for the LimeFM link and below this the 2 folded dipoles of LimeFM. The VK5RNC vertical link antenna to the Bluff can be seen to the right and half way down the tower the UHF link yagi to Wilalooka.
Old antenna off. Examination at ground level showed considerable corrosion for the 30 year old antenna
The support pole for the new antenna installed
Our two new phased dipoles in position
The finished job. Our two link yagis can be seen near the bottom of the photo. The Bluff link is vertically polarised while the Willalooka link is horizontally polarised.

Surprisingly there does not seem to be any interaction between our installation and the LimeFM 100W transmitter/receiver. A condition for the LimeFM owners use of the site is they do not cause interference to us. So far they don’t.

It’s a good outcome and signals around the area do seem to be up. Time will tell.

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