3600 miles, 100 milliwatts, 5Hz of spectrum near 10MHz, rooftop mounted dipole, $25 of parts to make radio (including obligatory Altoids tin) => 0.05 bits per s

3600 miles, 100 milliwatts, 5Hz of spectrum near 10MHz, rooftop mounted dipole, $25 of parts to make radio (including obligatory Altoids tin) => 0.05 bits per second. [Edit: to lose that extra zero. Thanks Joe.]