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[82.70.254.222]) by smtp.gmail.com with ESMTPSA id v144sm12278121wmv.27.2017.07.01.09.46.41 for (version=TLS1 cipher=AES128-SHA bits=128/128); Sat, 01 Jul 2017 09:46:41 -0700 (PDT) Date: Sat, 1 Jul 2017 17:46:40 +0100 From: Chris Wilson X-Priority: 3 (Normal) Message-ID: <871968008.20170701174640@gmail.com> To: Andy Talbot In-Reply-To: References: MIME-Version: 1.0 X-Scan-Signature: ce0e5a4ae990e5a63db3ab7aea21191b Subject: Re: LF: 20 Years of QRSS Content-Type: text/plain; charset=utf-8 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.75 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by lipkowski.org id v63LhJGS002462 Status: O X-Status: X-Keywords: X-UID: 12158 Hello Andy, Well, fascinating history there, congrats on all that, but you are showing your age a bit ;) What's this new WSJT mode "FT8" all about? Too wide a bandwidth for LF, or of interest, anyone know much about it yet? Saturday, July 1, 2017, 5:34:05 PM, you wrote: > Looking back in my logbook I see on the 12 July 1997 that I made a > transmission on 73kHz that was received by G3PLX 393km away in a > bandwidth of a few tens of milli-Hz. Peter was using the new fangled > DSP stuff in a Motorola DSP card, to display the narrowband filtered signal on a waterfall display. > I was radiating perhaps 5 - 10 milliwatts ERP (from a 200W transmitter) > No information was exchanged that day, just confirmation of the > carrier being switched on or off using the telephone as a back link. > Peter suggested I write some software to generate very slow CW to > key the transmitter and send it to him. > On 27 July He received the first SLOWCW signal from me with > positive ID of the callsign, sent according to my logbook notes with > 100s dots between 0400 to 0718 UTC.    We then did the same again > for several nights running, varying the dot speed .   This > completely smashed the one-way distance record for the 73kHz band.   > There were several at the time who said "its not real amateur radio, > it's computers talking"  but those voices were soon silenced.  > Others wrote software to generate the keying and suddenly everyone > started using SLOWCW which for some unfathomable reason started to be called QRSS (why ?)  > Now 20 years later, it still seems to be widely used, albeit with a > few variations like DFCW to speed up exchanges. > Andy  G4JNT -- Best regards, Chris mailto:dead.fets@gmail.com