|
 From our home in Northam, Western Australia, I only have access to one repeater, VK6RAV, a simple converted Philips FM880 device on the 2-meter band located on Crowsnest Hill, about 10km outside of town. Since I've lived in Northam, this has been my main means of accessing amateur radio. Unfortunately, the repeater experiences periods of odd RF feedback that hold it open until it times out and produces a very annoying howling sound.
The repeater provides good coverage of the Avon Valley, including Northam and a few other towns, and serves as an important link for the sparsely scattered amateur community. However, this intermittent fault often makes it unpleasant to monitor the repeater when it acts up, which can last for days and result in little activity on the device.
My first contact through VK6RAV was shortly after moving to Northam. I was driving when I heard someone calling on the repeater using my Icon IC-W2A radio on the car floor. I quickly pulled over and made a call. The response came from VK3YE, who was train mobile near Northam. My first contact was with Peter Parker (VK3YE). I had a chat with Peter for about twenty minutes as his train passed through the Avon Valley on its way to Perth. It's a small world!
My first local contact was Jim (VK6CA) shortly after the contact with Peter Parker. Jim later invited me to attend a repeater working bee on
7 June, 2008, with the aim of replacing the antenna, as it was the only part of the repeater installation that had not been addressed in an attempt to resolve the fault.
This job required at least six people to manage the guy wires and mast winch for lowering the antenna mast, and we had eight local amateurs present on the day.
I was there in a heartbeat, as this was a great opportunity to meet most of the hams from the Avon Valley area. The job was also fun because I got to climb the tower and feel like I was contributing to my new community.
While replacing the antenna was a bit of a long shot, we gained some confidence when we found corrosion and oxidation in the antenna and antenna connection. The N connector at the antenna end of the coaxial cable rotated freely, which was not a good sign for a solid connection. The theory was that perhaps a strong local broadcast of a similar signal was producing harmonics and intermodulation within the connections, somehow affecting the repeater. Whatever the cause, it was very marginal and intermittent, the worst kind of fault.
Although the work went relatively smoothly, it took a bit longer than expected, and the tower was finally raised back into position well into the evening.
Unfortunately, the antenna replacement did not fix the problem. We had about four days of faultless operation, and then the fault returned for about an hour one afternoon. It was always a long shot, and now it's back to the drawing board!
There is anecdotal evidence from Barrie (VK6ADI) that the repeater's coverage has improved, as he has noted that a number of previously weak spots now have workable coverage. So, the work was not a complete loss.
For those in this part of the world, here are the repeater details:
Input:
147.875
MHz
Out
put: 147.275
MHz
Call
Sign: VK6RAV
Location: Crowsnest Hill
Coverage:
Avon
Valley
Power:
274m
This site is
about 10 km North East of Northam, which is about 80 km East of
Perth. The site is located on a wheat farming property on a small
hill known as Crowsnest Hill about 90m above the average terrain.
The VK6RAV is
operated by the West Australia Repeater Group. http://www.warg.org.au
See
current operational details of local repeater VK6RAV.
|
