What is the voluntary band plan restriction for US stations transmitting within the 48 contiguous states in the 50.1 MHz to 50.125 MHz band segment?
Only contacts with stations not within the 48 contiguous states✓Правильный ответ
Only contacts with other stations within the 48 contiguous states
Only digital contacts
Only SSTV contacts
Объяснение
The bottom of 6 meter SSB is kept clear for openings to stations outside the lower 48, which are rare and easily buried by domestic contacts. The restriction is a band plan agreement, not a rule, but it is what makes the window useful.