FT8 ... Such A Tease

Looking towards EU over Georgia Strait, last winter

With the continued tsunami of FT8 activity on the HF bands, I decided to have a look at what was happening in the FT8 segment of 160m.




On Saturday afternoon, about ninety minutes before my local sunset here in south west British Columbia, I set my receiver and 160m half-sloper to work, along with WSJT-X, on 1840kHz USB mode.

Although still in broad daylight, the waterfall was immediately flooded with signals! As I started to pay closer attention, I realized that many of the signals were from Europe! Many were audible while the rest were fast-approaching that level, being stronger than -20db. I let the receiver run for another few hours and took a screen capture of my PSK Reporter screen, illustrating what had been decoded over that time span:

courtesy: https://www.pskreporter.info/pskmap.html

Checking other NW or VE7 monitors during the same time span showed no EU decodes at all, which I found surprising ... perhaps I missed someone. My location here on the eastern shoreline of Mayne Island looks towards EU and many other directions directly over a large body of saltwater ocean, Georgia Strait. The photo above was taken last winter, through the living room window. It is also very quiet, electrically, with little or no noise most of the time.

It appears that the lack of man-made noise combined with the theoretical 6db saltwater horizon gain (being realized), is enough to allow these signals to be heard. Signals continued to be decoded as darkness approached but at around 1800 local time, began to drop off ... evidently this appears to be a sunset enhancement, similar to what I often see to the east coast on the 630m band.

Now here’s where it gets even more interesting, as my decodes for the ninety minutes before and after local sunrise indicated a similar pattern!

The most probable path for these signals, around sunrise, would be via the long path in darkness. Although there is no saltwater directly behind me, it seems that the 'quietness' may be enough to do the job. Here’s the slightly post-sunrise screen cap from PSK Reporter:

courtesy: https://www.pskreporter.info/pskmap.html

FT8 is surely a tempting seductress. So far I have resisted the fast-growing urge to spark-up in this mode on 160m ... but I may be growing weaker. This all looks so very interesting.