Antenna: 160 meters, Range: 1.8 to 2.0 MHz
Good 160 meters antennas are easy to build with nothing more than readily available materials. Since 160 meters covers the frequency range of 1.8 to 2.0 MHz you can use a few algebraic formulas to compute antenna sizes.
The use of 160 meters for survivalists is likely never to come about for several reasons. One reason is the size of antennas needed for the 160 meter band ar erather large. On HF communications radio operators generally use antennas that are one quarter wavelength for the band they wish to use. On 160 meters a quaterwave antenna is in the neighborhood of 130 feet. Shortemed verticals and dipoles are used with some sucess and there are some hearty souls who have develope massive beam antennas for 160 meters such as the one shown below.
Of course these 160 meter beam antennas would not be pratical for any type of survivalist communications.
Problem number two with 160 meters is that it is primarily a nightime, wintertime band dur to its propagation characteristics.