RTTY: Which Sideband?
Amateur RTTY uses two carriers, 170 hz apart; these two carriers are referred to as Mark and Space. By convention, the Mark carrier is the higher of the two frequencies. You can accomplish this by placing the radio on either sideband, so long as you ensure that the Mark carrier occupies the higher frequency. When using WinWarbler to operate RTTY AFSK,
if you've configured WinWarbler to direct Commander to place your radio in LSB when operating RTTY, the Reverse boxes in the Main window's RTTY receive and RTTY transmit panels should be unchecked
if you've configured WinWarbler to direct Commander to place your radio in USB when operating RTTY, the Reverse boxes in the Main window's RTTY receive and RTTY transmit panels should be checked
The primary reason for providing these Reverse boxes is to enable you to communicate with the poor soul who is calling CQ "upside down" and wondering why no one is responding.
When using WinWarbler to operate RTTY FSK, configure WinWarbler to direct Commander to place your radio in its RTTY FSK mode; the Reverse boxes in the Main window's RTTY receive and RTTY transmit panels will be disabled ("greyed out").
Getting Started with CW, Phone, PSK, and RTTY Operation
Setting up CW, Phone, PSK, and RTTY Operation