Use a longer recovery delay where there are fewer targets, low trash and you want to go deep. It allows the deeper targets to come through. It gives them a chance to let the detector give a tone.
If you're in a trashy area, for example sidewalk strips, tot lots, playground grassy areas, etc, you'll want a shorter recovery delay so you can hear the good targets next to the nulled out ones.
SAT is self adjusting threshold. It works the same on the Spectrum (VX3 and V3i) as it does my GMT. As you increase SAT then the quicker the detector will return to threshold. If your SAT is too high, deep targets might not even give a tone because the SAT will return your detector to threshold too quickly. SAT isn't applied to Pinpoint, only the all-metal programs like Prospecting or a mixed-mode program you've made yourself.
The best way to experiment is test a few targets that you desire to find by burying them in the ground. For example, I buried some 14k jewelry I found at the beach in my back yard. I set up a little testbed for my GMT. The initial setting for the SAT on the GMT is 3-1/2 on a 10 scale. I noticed that in my ground here in Florida, the GMT really likes 14k gold jewelry (even the thin stuff) with an SAT setting of 4-1/2. I was using the GMT's stock 6x10 DD Goldmaster coil.
