On Sat, Jan 10, 2015 at 10:13:20PM +0000, Alan Melia wrote:
> Hi Pieter, Dave G3YXM and I did some quick and dirty estimations of
> QRSS about 10 years ago on 136kHz I cant remember whether we did
> DFCW where the main advantage is that it is faster, but the decode
> threshold is about the same as QRSS It is a little subjective but
> the results seemed reasonably what we might suspect.
>
> They may be on his web-site still www.wireless.org
Found it, at http://www.wireless.org.uk/signoise.htm . No DFCW there though.
The QRSS line in my table is based on ON7YD's tests,
http://on7yd.strobbe.eu/QRSS/
> I believe someone in the States also did some tests, John W1TAG
> could probably help there. They may be on the LWCA web-site.
I'd be interested, but can't find something relevant on the LWCA site.
B.t.w., what I wrote earlier about DFCW is wrong; I somehow thought DFCW
was simply morse code sent using FSK instead of ASK, but it's different,
using 2 tones for dots and dashes. Hard to say what this does for the
required SNR and Eb/N0 compared to CW, as both the average power and the
data rate increase.
73, Pieter-Tjerk, PA3FWM
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