The SSB modulation came to the telecommunication in the purpose of
saving frequency spectrum and reducing transmitting power without
sacrificing the signal intelligibility. It seems to me that during the
years and decades the knowledge of processing the signal for optimal
communication grade frequency/power spectrum has almost vanished down
and under.
Fortunately, at least our clever software wizards still understand
better than we, the appliance operators, what and how to do it for
HF-ham radio communication. I uploaded to my homepage a couple of
ancient articles that may be fun reading to the newcomers for the basic
understanding why and how the signal has to be processed:
http://kotisivu.dnainternet.net/ahti/sdr-1000/speechproc.pdf
http://kotisivu.dnainternet.net/ahti/sdr-1000/filtclip.pdf
The first article is amateur radio oriented and from ZL1BN in Ham Radio,
February 1975. This and the more recent good work of our AGC guru, Phil
VK6APH, shows that the real understanding has survived well "down under"
in Australia and New Zealand. Now the ideas born in the tube (or valve)
age are experiencing a rebirth with the better tools of DSP and the Flex
software team working as the "midwives". Thanks FlexRadio letting this
happen!
Happy Boxing Day and 73, Ahti OH2RZ
