Message-ID: <003201c088fd$280b3360$0301a8c0@steve>
From: "Steve Olney" <ollaneg@zeta.org.au>
To: "RSGB LF Group" <rsgb_lf_group@blacksheep.org>
Subject: LF: Fw: [Lowfer] Proposed new LF signal format
Date: Sun, 28 Jan 2001 18:37:17 +1100
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Oops, I meant to send it to the group !!!

----- Original Message -----
From: Steve Olney <ollaneg@zeta.org.au>
To: Stewart Nelson <sn@scgroup.com>
Sent: Sunday, January 28, 2001 7:57 AM
Subject: Re: [Lowfer] Proposed new LF signal format


> G'day Stewart,
>
> Great stuff !!!  Once again the US LowFer mentality has produced some
> quality work (don't work harder, work smarter).
>
> Your knowledge and analysis are beyond my capability but it sounds good.
I
> won't be able to evaluate it though as my spare time is totally committed
to
> building up a FDK beacon (hardware and software) for evaluation.
>
> I wonder, could you find time to do an evaluation of my FDK method
compared
> to QRSS (0.4wpm, say) and your method.   I know you are familiar with it,
> but I will repeat the method here.    Two tones are sent simultaneously
for
> one minute to encode a single character.   The operator (or the software)
> need only pick out the two highest amplitude tones from a one minute
> spectral analysis to receive the character.  I have beta tested some
> enhancing algorithms (I call smart-scan) which seem to work well, such a
> centre frequency tracking to allow rejection of tone pairs which don't
have
> a centre frequency close to the tracking centre frequency as well as
> truncating the scan bandwidth around the centre tracking frequency.  Also
a
> run length integrator (but of course using mode, not mean) really lifts
the
> performance.
>
> Without all those algorithms, the bare FDK works down to -43dB S/N on my
> tests (I don't know how accurate that is, you and Kyle could better
evaluate
> it) while receiving a character/minute.    I haven't evaluated it's
> performance with the enhancing algorithms.
>
> Good work !!! Keep it up !!!
>
> P.S.   I also think that long-term integration techniques with high
quality
> frequency and time control will bridge the gap across the Atlantic (maybe
> not first due to the vagaries of LF propagation) but certainly on a more
> consistent basis.    As you know I have been pushing the narrowband barrow
> for some years now.  Who knows maybe some day across the Pacific (must not
> let ourselves be limited by reality).
>
> 73s Steve Olney (VK2ZTO/AXSO - QF56IK : Lat -33 34 07, Long +150 44 40)
> =============================================
> HomePage URLs:
> http://www.qsl.net/vk2zto
> http://www.zeta.org.au/~ollaneg
>
> Containing:-
> ULF, ELF, VLF & LF Experimentation
> InfraSonic Experimentation
> Laser Comms DX
> Amateur Radio Astronomy
> =============================================
>