Tuesday, 21 September 2021

Up early - to no avail!

Equinox is not only a good time for long path radio, but is also convenient, as you don't have to get up too early!

WSPR from the previous day narrowed down the peak long path signal time between 06:50 and 07:10UT.  

Around sunrise, facing the long path to the south west.
 

I was out and ready to communicate by 06:30UT.

Sadly, there was a hell of a lot of noise on the 20m band - for reasons I can't fathom.  Even FT8 was a struggle.  The same was reported in Australia by Peter Parker, VK3YE, who kindly responded to a call for a sked online the previous day - and who consequently couldn't hope for a QSO.

But there was an interesting simultaenous long and short path reception - almost impossible to say where the station was, but there are good hints of a ZL or VK accent at times. 

If you listen with good headphones, you can hear the echo and, from time time, very rapid, brief changes in signal strength, which seem to be primarily down to phase differences, probably interactions from the many paths taken under antipodean focusing.  The focusing happens when radio waves go off in all directions - such as they do from an omnidirectional vertical as I use -  and end up meeting again under spherical geometry at the antipodean point.  A directional antenna is actually detrimental to this propagation mechanism, often very significantly so.

I did manage to listen to VK3QN on WSPR at 07:20 and 07:30UT.  The difference in latitude, even when small, is critically important as to signal strength received at long path time.  Even so, I was hearing Ian 26dB stronger than the UK median SNR at 07:20UT, and 20dB stronger at 07:30UT.  Being by the sea is worthwhile!

1 comment:

PE4BAS, Bas said...

Nice recording. Definitely Australian or New Zealand accent. Wouldn't be surprised if someone reported long delayed echos at that time. Noise looks like there is a big thunderstorm somewere... 73, Bas