WSPR, 80m SAD and "high angle" prop mode...

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f6irf's picture
Last seen: 12 years 11 months ago
Joined: 2008/04/18 - 12:24
WSPR, 80m SAD and "high angle" prop mode...

Thanks for your massive participation to the 80m SAD.
As you may have noticed, I was using 2 antennas on 2 receivers:
-IRF RX-only station was connected to a Mag-loop 1m high. This antenna has a NVIS pattern, which is obvious looking at SNR's fm closely located stations (ie HB9CZF and a few others)

- The main station was alternatively connected either to the vertical (outside US-windows), and to a K9AY-loop (half-size) oriented NW.
I just selected 9 US stations, which I received during the all US-window on both antennas (some 550 spots). The distances involved vary from 5200 to 7500 kms.

- On those 9 DX stations, in the middle of the night, the K9AY provided some 5dB average better SNR's than the magn-loop.
- Near sunrise, the magn loop took the advantage, and was almost the only one to provide spots more than 1 hour after the sunrise.

It seems to confirm the hypothesis expressed by several "low band specialists": Near sunrise a NVIS antenna works better than any low angle antenna (including long beverages).
What I think is relatively new, is that this NVIS-improvement does not only concern antipodal stations sharing a common greyline with their correspondants, but also stations in the range 5000-7500kms located accross the greyline.

more on
73's and CU on 160m