First C4FM SOTA contacts in Queensland

Going through the Activator Roll of Honour results for QLD recently, I noticed that there were no results for Digital Voice. Checking the state of play for the other states, I saw that the Australian Capital Territory and Victoria had one each.

It was time to put that right, so on Saturday 23rd June, I headed out for Mt Cotton (VK4/SE-115) with nothing more than my Yaesu FT-70DR hand held radio.

I had activated this summit more than a year previously, so if I logged at least four qso’s, it would count as another activation and my tally would increase by one point.

The climb up to the summit was uneventful and I headed to a clearing that featured a rather tatty picnic table and a good view.

I set the radio’s frequency to 147.400, the calling frequency for digital modes, and the mode to DN (Normal Digital Mode).

I had pre-arranged with Wal, VK4CBW, to listen out for me on simplex. His was the first contact I made. The distance between us was 26.33 Km (16.456 miles) and his Yaesu FT-2DR connected to a beam antenna sounded excellent. I ran a few quick tests too, to see what difference it would make to the signal if I placed my radio flat on the ground while he spoke. It made absolutely none!

Trying to get more height when calling CQ.

I am well used to using FM simplex on summits and noticed immediately that with C4FM there was no background hiss at all. The audio was as perfect as can be, very similar to that of a mobile phone.

I then had a long qso with George, VK4HGT, followed by Phil, VK4MOT and Bob VK4YA. All contacts were remarkable in that the audio was perfect. I think C4FM is far superior to FM analogue and it’s a mode I’ll be using more often in future.




Thinking about C4FM

I have noticed that activity on the HF bands has been very poor over the last few months. So much so that I hear absolutely nothing on 80m and minimal DX on the other bands.

At first I suspected my antenna, which is a long wire. But I do get good reports from DX stations that I am able to work. Then I started noticing reports about low solar activity. I came across an article entitled entitled Cooling Kills: Governments Must Shift to Cold Preparation by TOM HARRIS and DR. MADHAV KHANDEKAR:

Of particular concern are the warnings from solar scientists that over the next three decades, we are headed toward significant global cooling as the sun weakens into a grand minimum. The last time the sun was as weak as solar experts predict will occur starting after 2030, the Earth was in a particularly cold phase of the Little Ice Age that lasted from about 1350-1850, a period when there was great misery around the world.
Tom Harris is Executive Director of the International Climate Science Coalition. Dr. Madhav Khandekar is a former Research Scientist with Environment Canada.

This got me thinking. If their predictions are correct, we can expect reduced HF activity. However, I have also noticed that VHF/UHF FM activity seems to perform okay. This, together with the notion that technology is fast evolving, I think I will look deeper into C4FM technology. This is basically a digital FM mode that allows for the transmission of voice as well as date communications, using commercially available equipment. In the amateur radio domain, Yeasu have just launched a range of transceivers that I plan to purchase, once I have sold off my HF gear to make space on my workbench.

Watch this space.