Back when I was in Civil Air Patrol, I was given some insight to the use of the ADF. The one I used during field training looked like a broomstick with a radio box attached in the middle with [of course] the antennas. At a certain frequency, you could only align yourself with the flow of the transmitting signal. You then have to switch to another frequency [or maybe unplug the antenna] so that you can then listen [very carefully] for a beeping signal while you turn around 360*. The flow of the signal goes both ways, but the flow of the beep travels one way. Your body [with the box to your chest] blocks off the beep noise. That's a sign that the signal is probably coming in from behind you.
However, this is all I can remember from over 3 years ago. I will be surprised if what I described was accurate.
