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Can someone explain why nobody uses upper sideband?
- Thread starter Red 5
- Start date
As you may or may not know, 27 cb frequencies was originally a ham band. They used USB as per their band plan.
When i became a cb operator some 40 odd yrs ago a Ham guy told me cb'ers used LSB in defiance of the ham radio people.
When i became a cb operator some 40 odd yrs ago a Ham guy told me cb'ers used LSB in defiance of the ham radio people.
In Australia (where i am from) our band plan (by gentleman agreement) is lsb from 40m down and usb for everything else. including 60m.
... And are a little bit Inverted ...
Just for "giggles" I found this in the big "Lou Franklin" book.... for whatever it is worth....
"Note that LSB inverts the signal: the higher the modulating frequency, the lower the RF frequency, while USB is directly proportional to the modulating frequency. In the early days of radio that made LSB more difficult to process at higher frequencies. This led to a traditional use of LSB below about 10 Mhz, with USB above. There is no longer any technical reason for this, but the tradition is still generally observed today; most HF operation is USB. Interestingly, the FCC certification only requires that the transmitter be capable of USB; LSB is optional for the manufacturer."
I do note that on my IC-7300 when I go to 80 or 40, LSB is the default mode selected. 20,17,15, 12 and 10 USB is the default. You can of course switch those defaults if you wish.
"Note that LSB inverts the signal: the higher the modulating frequency, the lower the RF frequency, while USB is directly proportional to the modulating frequency. In the early days of radio that made LSB more difficult to process at higher frequencies. This led to a traditional use of LSB below about 10 Mhz, with USB above. There is no longer any technical reason for this, but the tradition is still generally observed today; most HF operation is USB. Interestingly, the FCC certification only requires that the transmitter be capable of USB; LSB is optional for the manufacturer."
I do note that on my IC-7300 when I go to 80 or 40, LSB is the default mode selected. 20,17,15, 12 and 10 USB is the default. You can of course switch those defaults if you wish.
In 1962, when I upgraded from Novice to Conditional class (General taken by mail), I'd usually get up well before leaving for high school and see what was going on on 15 meter CW. Didn't have an AM or SSB transmitter and didn't want one; CW was fun. Then I'd cautiously move up to 10 meters and frequently drown in DX. Ah! The good old times!