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Yes, I was comparing apples to oranges but just wanted to illustrate that 100 mW. or so is not such a low power under the right circumstances.
For those who are interested, I have read accounts of hams operating QRP (low power) on 160 meters (1.8 MHz.) with 100 or so mW. and with appropriate antennas (vertical masts if I recall, 60 feet or so) have been heard 180 miles away. They were using some sort of ultra low bandwidth digital modulation. I don’t remember the details but I recall the bandwidth was about 1/2 Hz.
Narrow bandwidth gives an advantage when the signal is extremely weak and is used by NASA for space probes. At NASA frequencies the noise is proportional to the square root of the bandwidth (among other things), so small bandwidth improves the S/N ratio. The signal from the Pioneer Probe used a bandwidth of 10 Hz. Morse code takes more than that.