In what segment of the 20-meter band are most digital mode operations commonly found?
Why By long-standing band plan convention, the digital data modes on 20 meters cluster just above the RTTY/CW portion, in the 14.070 to 14.100 MHz range. That is where you find PSK31 near 14.070 MHz and FT8 at 14.074 MHz, with the segment ending at 14.100 MHz where the NCDXF international beacons operate. These are voluntary band plans, not FCC rules, but everyone follows them so digital signals can find each other.
Watch out The 14.230 MHz choice is the well-known SSTV calling frequency in the phone segment, and 14.325 MHz is voice as well, so neither is where keyboard-to-keyboard or FT8 traffic lives.
20 m digital: 14.070 to 14.100. Remember 14.074 for FT8 and 14.100 for the beacons that cap the segment.