You can also increase the depth by about 3/4" and even more. I'm getting 1 1/4" on a dime with mine and by using some sort of metal object, I used a thin piece of brass that came off a school ruler, and by using a rubber band around the back of the unit and slip the metal piece under the rubber band. Pull the metal piece towards the rear, turn on pin pointer, slide metal piece forward until it starts to chirp, slowly slide the metal piece to the rear until it stop chirping. I can usually get 2 to 2 1/4" or more by using this crude adjustment but it works for the times you might want or need a little extra depth.
I also have read the reviews about people getting from 1 1/2" to 2"+ on a dime but this is the results I'm getting on a newer unit. I emailed Garrett and was told I should be getting more than 1 1/4" on a dime and for me to send it in and it would be replaced. The new unit arrived a week later and still it will only get 1 1/4" on a dime.
While checking the depth on coins I again rechecked the dime and on the second depth test now I was getting 1 1/2" and the rest of the coins were also getting more depth. It finally dawned on me that the longer the unit is on the more depth it gets. I retested it. I turned it off and let it sit for a few minutes and within 10 seconds of turning it on I tested the dime again and the depth was as follows:
0 minutes - 1 1/4"
1 minute - 1 3/8"
2 minutes - 1 5/8"
3 minutes - 1 15/16"
4 minutes - 2 3/8"
5 minutes - 3" moments later the unit became unstable and started chirping and vibrating all my itself with no metal anywhere near it and had to be turned off.
I have repeated this several times with almost the same results and have had other people try this with their units and they also have had about the same results. Now normally you don't keep a PP on for this long and it was for test purposes only. This might also explain why some people says 1 1/2" and other say 2". Also it may be the older units were hotter than the current units. Now I'm not bashing the PP I just thought this was interesting myself and I don't know if all units will do this.
Love mine! It's great. I have dug three silvers in the last month and haven't come close to scratching one of them. For that matter I don't think I've scratched a coin old or clad in the last two months.