Marine VMC Charleville (AUS) 12365 kHz weather forecast and other grayline fun


Sep 27, 2021
(Repost from the SWLing Message Board)

A few weeks ago, while spending an hour or two with my little Belka and just its whip at my listening post at the (German North Sea) dike I stumbled upon 12365kHz - I heard a coastal weather transmission in English with a signal that made me believe it would be from the UK or the US <shrug>. Obviously, I wasn't familiar with that frequency but looking it up back home it turned out to be - of course - VMC Charleville (Queensland, eastern Australia), the sister station of VMW Wiluna Radio (which is in western Australia). Both stations are strangely not located at the coast at all:


Two days later I drove to the dike again to scan the bands for an hour or two, remembered that station and tuned in 30 minutes after the full hour - it was even louder (again on the whip), peaking above 40dB/uV on the meter. The noise was around 5, so that's 35dB SNR -- enough for very comfy listening without missing a word. Unfortunately I forgot to bring my cellphone (again!) so I couldn't record that nice signal from (almost) the other side of the globe, some 10,000 miles or 16,000km away.

On Thursday and Friday evening I went to the dike again, this time with my cellphone ready for recording. But when the VMC came on at half past the hour it was barely audible due to some solar radiation storm and still nothing to phone home about the next evening, you guys all know that classic story.

Saturday the conditions had recovered so far that I could at least hear some of the IBP beacons again, besides 4X6TU (which is always there) very grass roots signals from Sri Lanka and Japan, but none from Australia or NZ. At the same time as the days before (2130Z, in the grayline zone) I switched to 12365kHz and got a serviceable signal:

When I looked around for the sister station VMW (Wiluna) in western Australia on 12362kHz I could pick it up only much weaker. This could be explained with the station being 1,600 miles/2,500km to the west and possibly too far off the grayline at that time. But I heard station VIC ("RCC Australia" in Charleville again) responding to a radio check request by some vessel they called "Sea Force"):

Back home I tried to find some VMC reception videos on YouTube and found a few. The only videos getting close to that signal quality were made with considerable antennas or they were recorded in Australia. I like to keep on rambling about how good the Belka is and how "the dike" and its 10dB "ocean gain" is a deciding factor. But... if you subtract the 10dB ocean gain from the signal, you still have a comfy signal despite the rather mediocre, only grayline enhanced conditions. On the puny whip -- it keeps boggling my mind every time! :)

Until 2300Z (1:00am local) I also caught some satisfying ham bycatch with the whip. The clip starts with some signals from the Americas (the other side of the grayline for me), which are not at all unusual (particularly not for you guys on the other side of the pond) but they serve as a reference for the Australian:

2023-07-29/30 dikeside random DX bycatch

Among those there were stations from Japan that came in short and long path at the same time. Here's JH3NGD (Kazu-san) as an example:

JH3NGD on 17m simultaneously short and long path reception

You can hear the echo from the long path (max. ~31,000km or 19,000 miles) signal arriving ~100ms later than the short path signal from Japan (~9,000km/5,600mi). First time I heard this on the whip. But why I'm really posting this is -- bringing just a small portable to places away from civilization can be quite rewarding, even if you have a good rig and relatively low noise levels at home. 10dB less noise can make a world of difference, 20 dB two worlds and so on... do it! :)