I have been using my Fisher F5 almost exclusively for the last two months and have dug some pretty deep coins in that period. I believe that you have to get your ears and brain programmed to what a deep coin sounds like with any detector. For me, that is a problem because my detecting spots have been hammered by me and many others, so most of the older, deeper coins are long gone. This week was an awakening because I finally got a bunch of deeper coins under my coil and the F5 did not disappoint. Like it's brother the Omega, the F5 does not scream out on a 7 to 9 inch coin, but gives a weak, but distinct high tone tick(I hunt in three tones) that usually repeats from all angles. When something is fresh in your brain, it is easier to get comfortable with the sounds and this last weeks finds really helped me. I did not find anything out of this world, but I did have one "heart stopper" a couple of days ago. I got one of these very faint ticks that had numbers between 85 and 91. It pinpointed very tight like a deep coin and sure enough it was silver. A 1916 mercury dime with very little wear. I was shaking as I turned it over looking for the "D", but not to be. This is my 4th plain 16 along with one "S". I also have found a dozen 8 to 9 inch deep wheats and two silver roosies. I will pass along my settings as I run my F5 on thie edge of being stable. Sens 85, disc 15, no notches, three tones, and what I find to be very important for getting the most depth out of this detector, the threshold at 0. With these settings, the detector will chatter when you stop swinging it or set it down to dig. You will hear some noise while swinging, but you can pick out the tones if you concentrate. It might not be for everyone, but it will get you to the 8 inch plus depth level. This detector is one of the best coin detectors I have ever used and I have used just about all of them out there.