G'day All,
To add a bit more info about VFSKCW, some advantages I noted in the earlier
experiments (I haven't done any lately) was that under marginal conditions
(e.g. QRN) I found VFSKCW easier to copy than QRSS. This was because the
QRN can easily "fill in" a space making it difficult to distinguish between
two dots and one dash. By inceasing the dot length such that the time for
the overall QSO is the same as QRSS, these QRN crashes can more easily
rejected than QRSS. In addition, the actual fact that information is
largely carried not in the absence of signal, but the presence of the
signal displaced, makes it easier for me to discern the pattern. Bear in
mind that I cannot read morse by ear and only read the screen in terms of
dots and dashes. It may be easier for me to do this as I have not been
programmed to associate morse with sounds. I don't know. I did not do any
quantitative evaluations at that earlier time, but you guys will be able to
verify/refute this with actual tests. I am handicapped here as the nearest
LF station is over a 1000Km away and do the tests by mixing external noise
(including QRN) with the LF signal (reduced by an attenuator).
Any feedback would be most appreciated.
73s Steve Olney (VK2ZTO/AXSO - QF56IK : Lat -33 34 07, Long +150 44 40)
=============================================
LowFer URL:
http://www.zeta.org.au/~ollaneg/lowfer.htm
AXSO LF Experimental Station URL:
http://www.zeta.org.au/~ollaneg/axsoextx.htm
LF Receiving - FRG-100, CHA antenna
LF Transmitting - 177.5/177.4kHz 8W - 7.6m vertical or CHA
Modes - AM, SSB, PSK31, SSTV, Hellschreiber, QRSS
and a new experimental mode - FDK. See this URL for more:
http://www.zeta.org.au/~ollaneg/FDK.htm
=============================================
|
