I'm measuring about 0.016 fT daytime, 0.045 fT nighttime.
Daytime signal phase leads the night phase by about 67 degrees.
Combining and normalising day/night signals and excluding
the terminator periods gives
http://abelian.org/vlf/tmp/170809a.gif
Still not significant, only about 3.5 sigma, 10.9 dB S/N
in 1.13 uHz.
> Seems the result is even poorer than on 2.97 kHz?
Probably just because I'm not using the E-field.
> i would try some first EbNaut on that 82 km band over
> to DL0AO in 226 km.
Yes, if the S/N is good enough at DL0A0. Not much use continuing
with carrier when I only have half a receiver.
This afternoon I'll do some more work on the new E-field rx.
Running side-by-side comparison with the old rx.
I've been working on the new rx for over 2 years but the system
noise is still consistently 0.1 dB worse than the existing rx.
The front-end noise of the new rx is lower but the bandwidth is
wider. The extra signal is raising the noise floor slightly
due to a tiny amount of distortion in the line driver and
isolating transformers. On the test bench the new rx does very
well: very low noise and low distortion. But with the full
signal from the antenna there is enough mixing to slightly raise
the noise floor. I just need that 0.1 dB and also to cure some
mechanical noises (microphonics) when the wind blows.
PS, the new rx also also covers 137 kHz!
--
Paul Nicholson
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