WSPRing at the 1 micro watt level.

Greetings fellow WSPR enthusiasts ....

I have been experimenting with ultra low power transmissions on 80M.
In particular, between my QTH (Saratoga CA, near San Jose) and a former marine radio station KPH.
KPH is located 123 km from here, heading 320 degrees, on the CA coast. (http://www.radiomarine.org/)

For unknown reasons the propagation between KPH and this QTH can be exceptionally good
and quite repeatable. A Virtual Waveguide might be a good description.

Yesterday, two spots were logged on 80M between KPH and w1qg using 1 microwatt.
This was chronicled by way of a (crude) YouTube video.
You can find it here: https://youtu.be/GtiueLaKZes

Yesterday, it became clear to me that I probably missed the propagation "sweet spot".

The experiment was repeated this AM and here are the results:

UTC TX txGrid RX rxGrid MHz W SNR drift Km Km/W SpotQ
------------------------------------------------------------------------------------------------------------------------
2019-09-10 17:00 W1QG CM87xg KPH CM88mc 3.570046 0.001 -30 0 123 123000 127241
2019-09-10 16:44 W1QG CM87xg KPH CM88mc 3.570046 0.001 -28 0 123 123000 135724
2019-09-10 16:32 W1QG CM87xg KPH CM88mc 3.570046 0.001 -31 0 123 123000 123000
2019-09-10 16:22 W1QG CM87xg KPH CM88mc 3.570046 0.001 -29 0 123 123000 131483
2019-09-10 16:20 W1QG CM87xg KPH CM88mc 3.570046 0.001 -28 0 123 123000 135724
2019-09-10 16:12 W1QG CM87xg KPH CM88mc 3.570046 0.001 -29 0 123 123000 131483
2019-09-10 16:10 W1QG CM87xg KPH CM88mc 3.570046 0.001 -29 0 123 123000 131483
2019-09-10 15:36 W1QG CM87xg KPH CM88mc 3.570046 0.001 -28 0 123 123000 135724
2019-09-10 15:28 W1QG CM87xg KPH CM88mc 3.570046 0.001 -2 0 123 123000 246000
2019-09-10 15:18 W1QG CM87xg KPH CM88mc 3.570046 0.001 -5 0 123 123000 233276
2019-09-10 15:10 W1QG CM87xg KPH CM88mc 3.570046 0.001 -6 0 123 123000 229034
2019-09-10 15:02 W1QG CM87xg KPH CM88mc 3.570046 0.001 -4 0 123 123000 237517

Between 15:02 and 15:28, the TX power was 1 milliwatt. After 15:28 the power was lowered by 30 dB to 1 microwatt.
The 8 spots that follow (15:36 .... 17:00) were all at the 1 microwatt (-30dBm) level.
The SNR change clearly shows this power reduction.
Please note that WSPR does not correctly report powers less than 1 milliwatt.
See the Q&A forum for a short discussion on this topic.

Station info is covered in the YouTube video if you are interested.

Good DX and best regards to all,

Dick / w1qg