Re: VLF: EbNaut transmissions on lower frequencies?, pre-tests: 6.47kHz

[Paul Nicholson <vlf0403@abelian.org>]

Message 'ROCK N ROLL' 16K25A 30 seconds repeated 3rd and 5th Nov:

                   3rd               5th             3rd+5th

 Eb/N0            -5.4 dB         -5.0 dB            -2.3 dB
 S/N in 19.7uHz   12.5 dB         13.0 dB            15.7 dB
 Absolute phase   -120.7 deg      -130.0 deg        -125.1 deg

Eb/N0 above is calculated from the carrier S/N not the bit errors.
The combined signal actually decoded at Eb/N0 = +0.3 dB, partly
due to the extra symbol normalisation.

Message 'SUCCESS' on 2nd Nov 30 seconds 16K25A

 Eb/N0              1.7 dB
 S/N in 25.4uHz    16.1 dB
 Absolute phase   -121.1 deg

We appear to be a getting a quite repeatable phase, day to day.

Decoded today 'TEST' at Eb/N0 = +8.5 dB.

Another from October:

12 Oct 8K19A 40 seconds 3 chars, decoding '73S' at Eb/N0 = +0.1 dB
with phase pattern 90 120 120 150.

--
Paul Nicholson
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