Re: VLF: EbNaut 8270.0025 Hz

[Markus Vester <markusvester@aol.com>]

I had started the carrier at 11 UT, and have left it on after the EbNaut sequence (hopefully until 22 UT). As expected, the signal level is fairly constant in Amberg, but it has been steadily increasing during the afternoon in Heidelberg, So it looks like we are again seeing the "midday minimum" effect from antiphase skywave. Interestingly, it appears to be more pronounced than during Stefan's long carrier transmission on Jan 28/29. I can think of three possible reasons:

1. My signal is weaker and closer to the noise, so a shallow minimum might simply be more conspicuous,
2. Increased solar elevation in April versus midwinter produces a lower and sharper D-layer boundary. This would strengthen the reflection, and the shorter delay might bring it closer to antiphase,
3. Stefan is receiving on a loop, which should be 3 dB more sensitive to 45° skywave than my E-field receive antenna.

Best 73,
Markus  

 
-----Ursprüngliche Mitteilung-----
Von: Markus Vester <markusvester@aol.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: So, 30. Apr 2017 15:48
Betreff: VLF: EbNaut 8270.0025 Hz

Another short EbNaut test for DL0AO:

Frequency 8270.0025 Hz (same as preceding carrier),
5 characters 8K19A,
5 second symbols,
start 17-04-30 14:00:00, end 14:42:40.

See http://df6nm.bplaced.net/dl0ao/VLFgrabber/vlfgrabber_dl0ao.htm

Best 73,
Markus (DF6NM)