Just a further thought. WSPR doesn't of course spread its power over
6Hz it actually transmits full carrier on each of the four
frequencies for 0.682 mS and sometimes several of the same element
follow without a break in carrier, which accounts for some of the
bright spots and lines we see when things are marginal. One element
is a longer dot time than 2WPM Morse, and that is SLOW Morse.
Long integration times are out of course.
73 Eddie G3ZJO
On 27/04/2011 18:58, Roger Lapthorn wrote:
Hi Eddie (et al)
It is highly unlikely you'd copy Andrew on VLF remembering that
the WSPR signal spreads around 6Hz in the transmission burst, so
the energy in any narrow FFT bin would be tiny. Also, this is
earth mode (I hope, as G6ALB does not hold an NoV to radiate at
VLF), so signals are propagating through the ground by conduction
and no significant amount of signal is radiated.
I'm still intrigued why the best reception here today was with my
80sq m vertical loop. This outperformed several earth electrode
set-ups here at the RX end, an E-field probe and a 30t loop laying
close to copper pipe work in the house! If the signals are coming
down the pipes then why don't these more direct means of coupling
to them work as well as (or better than) a vertical loop outside?
Odd.
73s
Roger G3XBM
On 27 April 2011 18:33, qrss <[email protected]>
wrote:
Great stuff Roger and Andrew
If you are RX'ing on an 80m dipole it may be worth a look
here, I would never say can't until I have tried. Bearing in
mind I should be able to observe signals which would not be
decode able on WSPR
I would appreciate a prior notification of times and exact
frequency of the WSPR signal of any further tests.
Keep it up.
73 Eddie G3ZJO
On 27/04/2011 15:19, Roger Lapthorn wrote:
As an experiment I changed over to my wife's laptop and
got immediate decodes of G6ALB's VLF earth mode signal
(3km) at -17dB S/N, suggesting the issue with lack of
decodes may be with my soundcard and not Andrew's.
1408 -17 -0.6 0.008986 0 G6ALB JO02 47
1410 -17 -0.6 0.008986 0 G6ALB JO02 47
1412 -17 -1.2 0.008986 0 G6ALB JO02 47
1414 -17 -0.8 0.008986 0 G6ALB JO02 47
1416 -17 -0.8 0.008986 0 G6ALB JO02 47
This is a very solid signal on the 80m square single
turn vertical wire loop antenna. Andrew is using 44W to
an earth electrode antenna.
73s
Roger G3XBM
--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
https://sites.google.com/site/sub9khz/
--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
https://sites.google.com/site/sub9khz/
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