by Robert Brand
I was interested to learn that the HAM VHF radio repeater that Laurie MacIlree built in Guam and a few of us installed at OTC Paddington is still going, but of course it has brand new equipment, a slightly different frequency and Laurie is still involved. VK2ROT is still the call sign and it is managed by the local HAM radio club, Waverley Amateur Radio Society. This from their website http://www.vk2bv.org
This club, formed in 1919 in the Eastern Suburbs of Sydney, provides those interested in the hobbies of amateur radio and electronics with facilities to meet and enjoy the company of similar individuals. Regular meetings are held at the well equipped clubhouse in Rose Bay and training is provided for those new to the field. Visitors to our meetings are always welcome.
The repeater now is housed in a small rack on one of the upper floors of the Paddington terminal and also has a UHF repeater:
VK2ROT Paddington 147.025 +600 FM 91.5
VK2ROT Paddington 438.575 -5MHz FM, AP25 91.5
This is the current repeater rack (image below) at the old OTC Paddington Terminal. Once we radio amateurs get a foot hold somewhere, you can’t dislodge us and you have to allow for expansion!
Photos courtesy of the Waverley Amateur Radio Club
Of course, I had a hand in calling it VK2ROT. I obtained the first repeater license for the OTC HAM Radio Club and since all repeaters in the state were in the VK2Rxx format I thought “Overseas Telecommunications” sounded right so I applied and obtained VK2ROT much to the annoyance of many of the HAM around the company who attributed the ROT with an unflattering word. No one had any humour back then…..
Since repeaters transmit and receive at the same time and often with the same antenna, very high grade filters are required to stop the transmit frequency from getting into the receive frequency and causing massive problems. Laurie built the cavities and shipped them, but until they arrived we had a simple solution. We shipped the Transmitter to Broadway and put an antenna on the roof. We linked the radios with regular circuits and E & M signalling and the transmitter was never going to be a problem. It operated in that rather uneven mode for a year or so before the beautifully hand made cavities were shipped from Guam. Like a organ pipe, these resonated with radio signals and were similarly tuned to an exact frequency and did their thing of rejecting signals very close in frequency. We linked the repeater to another US repeater once or twice, well before a modern system called EchoLink was created and it was probably one of the very first repeaters to ever link with a repeater in another part of the world.
HAM radio operators could be driving in both parts of the world having a chat via radio as if there were local to each other. This was over a decade before mobile phone technology
Possibly the first. It had been done between states in the US back then. Dave Coutts was very involved with all of this. The repeater was also hooked up with a repeater in Perth and also in New Zealand for the scout’s Jamboree Of The Air (JOTA). I am told that the original transmitter and receiver are around somewhere and possibly still in operation with another repeater. Laurie will be able to tell us.