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Bob, well I guess I'm sort if lucky on 29.5 as
there happens to be little QRM here from big utility stations, railway, etc.
Even local QRM has been scarce (though I hardly dare write that, as
one of our twenty-odd neighbour families may any time corrupt the frequency by a
nasty SMPS / battery charger / energy saving lamp / modem / you name it).
Extrapolating received Opds-2H levels to QRSS would result in needing
something like 10 minute dots, so not really encouraging.
Regarding 8.3 kHz: I guess everyone working there
is limited by antenna voltage / corona, and as you say usually not much power is
needed to get to that limit. Assuming same voltage capability (eg 30 kV),
going down from 29.5 to 8.3 you'll need to reduce current by a factor of
3.5, decreasing ERP by 22 dB. On the other hand, Paul Nicholson was able to
resolve your 2-minute dots on 29.5, thus in a quiet night, an 8 hour continuous
carrier on 8270 might just become detectable in Todmorden. In
addition, Paul's http://abelian.org/vlf/ lists
several online VLF receivers sending high quality audio streams, and I
reckon a reception eg by Mike Smith in Forest / Virginia would be quite
likely and good DX for starters.
73,
Markus (DF6NM)
Sent: Saturday, March 29, 2014 8:26 PM
Subject: RE: LF: Re: Bunch of detects!
Markus; 29 is about it for me. I like to see some of the
other modes get detected but so far just not enough signal for any real QRSS
from like Henny, and Hartmut. Your OPDS sure works but many still have
work to do to get detections at -52 or so. What QRSS speed would I need
for you to get a decent capture on 29 QRSS??? OP2HDS is going to be hard to
beat. The OPERA DS detects have been very impressive from your QTH and you
are in amongst other houses! Others have for the time being stopped work
on VLF reception. Hope next season there will be improvements in that
area. If I could run enough power on 9 kHz I would try it but I see very
nasty voltages being generated with this short ant. I'll go back to 29
tomorrow night with OP2H and hope for another detection from you and maybe
someone else T/A. Your the furthest European other than the Russians so
should see others with detections sooner or later I would
think-Bob
From: [email protected]To: [email protected]Date: Sat, 29
Mar 2014 20:04:44 +0100 Subject: LF: Re: Bunch of detects!
Bob,
thanks for the signal, nice to find all
those good detections!
Tomorrow? Swing low! For me, the
lower and slower, the better. And give the Opera guys a chance for a
TA decode on 29.5 kHz ;-)
Actually, why not go sub 8.3 kHz one
night, and provide a fair challenge to Paul Nicholson. All you'll
need to do is wind up a couple of kilometers of
thin magnet wire (say AWG26) on a plastic bucket ;-)
Have a good weekend,
73, Markus
Sent: Saturday, March 29, 2014 4:48 PM
Subject: Bunch of detects!
Markus;
Was easy to find clear spot with your grabber.
Condx seemed good and made a bunch of detects I see!
Will do again tonight
same freq.
If you want-maybe tomorrow try 74 or back to VLF 29kHz if
you want-Bob
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