BACKGROUND INFORMATION
I have been studying Tropospheric propagation since late 2002.
I was inspired
by the award winning paper written by Wally Howse VK6KZ “VHF, UHF AND
MICROWAVE PROPAGATION AND THE GREAT AUSTRALIAN BIGHT”. I remember first
printing out and reading this paper, after it was sent to me by Wally. The
information that it contains is amazing. I read it over and over again and each
time I would pick up on something different that would start my brain ticking
over. I
suggest that if you get a chance, read Wally’s brilliant
paper.
My other reasons for
studying Tropospherics were that I was just plain fascinated in this form of
signal propagation, but also because, at the time, I did not know when I could
expect good tropospheric conditions to occur, therefore I was a little lost as
to when I should be listening so as not to miss a duct opening.
All this lead to
thousands of hours of Tropospheric research, by way of 24 hour a day radio tests
and monitoring, weather observations and general study and research of
information pertaining to Tropospherics. I can now leave the shack at any time
having a pretty good idea about whats going to happen on the bands, VHF and
above in relation to the tropo conditions.
THAT FIRST MAJOR DUCT
I think that for many operators, they really do think that VHF UHF has a limited range. For most, you have to be in a certain situation or exposure to have that something click in your brain that says "hold on, I just worked 500 Km on 144 MHz with a hand held, I'm onto something special here".
I recall that while I was still at school in yr 10, my parents bought me a Yaesu handheld 144 MHz transceiver for Christmas (around 1991). Though I had a vertical omni-directional antenna on the roof, I found myself walking to the top of the Hill in the center of Wagga to get better range. I remember being able to work across to Canberra, Albury and other repeaters. Sometimes I would work Rob VK1ZQR (VK1KW) on simplex from the handheld, around 150 Km.
The first major incident that occurred to me that started my curiosity into doing to the impossible on 144 MHz was back in 1993. On the 20th of December 1993, while living at my parents house in Wagga (NSW), I recall being able to work Bill, VK5ACY on Kangaroo Island, South Australia (900 Km). This was on 146.500 simplex FM from my handheld Yaesu!! I recall walking in the backyard and somehow working Bill, and also walking down the street out front of the house. I remember having such a strange feeling about this contact at the time and wondering how this just occured? but not thinking anymore about the incident at the time. Bill and myself swapped QSL cards in relation to this contact and I still have my card from Bill here.
VHF Long distance propagation potential was really hit home to me late at night on the 30th of October 2002, from my QTH at The Rock Hill (NSW). Lucky for me I had set the radio up in the bedroom and decided to leave it on all night. This was a Icom IC281H FM 2 m mobile rig and a 5/8 wave vertical at 30ft. At around 2 am that night, or the morning of the 31st, I was awoken by a signal coming up on 147.000 repeater. It seemed to slowly drift in and get stronger. I remember thinking, hmmm thats funny, the Albury repeater is not normally that weak (being on the same freq) so I keyed up and the Albury repeater came back over the top of the other signal. Oh my god! its not Albury.. it must be from some where else.... a few more mins of listening and signals were strong enough for me to hear callsigns. Stations talking were VK5MM, VK5ANP and VK5THA all in the Adelaide area, this was the Crafers repeater (764 Km). AMAZING! MORE INFO
So thats basically how my VHF UHF DX interest started. You really need to be on air at the right time.