Mike wrote:

the same way as they do on VHF. Just use a
quarter-wavelength of coax!!

or a 3/4 wavelength ...
Or - you could spin the loop really fast. (with slip rings for the signal)
For VHF DF they switch rapidly between four quarter-wave whips arranged in a
square, which gives a sort of rotating aerial - you could use FETs to switch
between the signals from two loops to do the same.
But this would introduce a new frequency - which you could use as a beat
frequency to resolve the cw.

Hugh M0WYE