05AB1E, 99 8 bytes
TÝžv+b€¦»
Explanation
TÝžv+ T # create the range [16# ...push 26]10
4ã b # cartesian #product convertrepeat towith binary4
R €¦ # removereverse list
T>£ # take the first char11 ofelements each
of the list
» # join withby newlinesnewline and display