Extra exam question E1A03

WhyThe highest legal carrier frequency for a 2.8 kHz wide USB data signal on 20 meters is 14.1472 MHz, keeping the signal's upper edge at or below the 14.150 MHz phone and image boundary. The 20-meter data/RTTY segment runs from the bottom of the band up to 14.150 MHz, with phone and image privileges beginning at 14.150 MHz. Since USB places a data signal's energy above its carrier frequency, a 2.8 kHz wide USB data signal has to have its carrier set low enough that the whole 2.8 kHz stays under 14.150 MHz, which works out to 14.150 minus 0.0028 MHz, or 14.1472 MHz, answer C. A carrier any higher than that would push part of the signal's bandwidth into the phone/image segment, and 14.3490 MHz is deep in the phone segment, nowhere near the data/RTTY boundary this question is actually asking about.