While out hunting today, I kept this thread in mind and played with the signals. I found that it really takes almost NO movement to get a signal from a real target. Every time I got a signal I would snail-crawl the coil over the spot and just listen. The signal may have given a little more wobble due to the slowness, but it was always a solid signal. When I got those blips and chirps that are typically iron falses, the snail-crawl would just give a null. If it gave a signal, it always resulted in a coin regardless of the iron in the spot.