Message-ID: <000701bfbbe4$a4acf840$22b1073e@dave>
From: "Dave Sergeant" <sergeantd@compuserve.com>
To: "rsgb_lf_group" <rsgb_lf_group@blacksheep.org>
References: <E12p5h4-0005In-00@mserv1b.u-net.net> <391AE0E6.F55B3603@netscapeonline.co.uk>
Subject: Re: LF: Spectran accuracy
Date: Fri, 12 May 2000 08:34:49 +0100
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>From Dave G3YMC

Mal G3KEV wrote:
>Had you been listening today you might change your mind. I tuned to a weak
>steady carrier and the QRN was so consistant that it  chewed it up
completely.
>Not just intermittent crashes but the STATIC was virtually continuous. I
then
>worked G8RW and gave him 259.

I cannot comment on the various pros and cons on Spectran's abilities of
copying signals under heavy static conditions (and must admit that recent
mails on DSP processors and other exoteric techniques leaves me rather
cold...) but I can concur with some of Mal's comments.  Over the past week,
when static levels have been horrendous, I have heard Mal on several
occasions.  Mal's signal is a little over s9 on my meter.  Many times the
static has been pinning the meter to 20dB over s9, with breaks to a lower
level for no more than 20% of the time.  At no time did the s meter go
anywhere its normal background level of s5.  In these conditions even Mal's
signals were rather fighting with the static and much chopped up.  However
because most of what he was sending was pretty predictable (ie a CQ call) it
was indeed perfectly possible to work out all the necessary information, ie
callsign, CQ, and if it were a QSO the RST, by piecing it all together in
the mind  (no need to write it down!). In basic QSOs, and certainly with the
limited number of stations on the band, there is a remarkable amount of
redundancy in our sending.  It may have been a little harder to follow the
guist if it were a detailed discussion of equipment changes etc, but for the
basic information necessary to qualify for a valid QSO it was sufficient.

If Spectran and the other programs offer the capability to copy stations
20dB below noise, in these circumstances this would only take you to s9,
which was certainly copyable with normal CW.  I admit the static levels
recently have been much higher than usual, and would not expect anyone to
attempt to work transatlantic under such conditions (or to even ragchew!)  I
have two weakish carriers on the band, 136.7 and 137.8 which are normally
just above the noise.  I wonder how copy of these is on Spectran with 20dB
over heavy static - I can just about copy traces here in the crashes.

Static is much lower this morning, can it last?

73s Dave
dsergeant@iee.org
http://ourworld.compuserve.com/homepages/sergeantd