I LOVE 4H tones...just love it!
I am a jewelry hunter by choice and will always be in my heart, gold is the metal that gets my heart beating and takes my breath away more than anything else.
I got my F70 the day after Thanksgiving in 2013 and used mostly 4H because it was the most similar to my F2...except for that high nickel tone thing.
On my first 4 hunts and about 10 hours I found many nickels more easily than with any other detector I ever held and I never really had any trouble finding nickels in the past.
I loved the nickels, at least they weren't trash but I was going after gold.
On that 4th hunt in a very trashy spot next to a picnic pavilion at a time when I still didn't really have a handle on the control or power of this thing as yet I came across a mixed signal, a little jumpy but I heard a short, quick high tone in it.
There was a piece of trash next to whatever was throwing off that high tone but by manipulating the coil I realized there were two targets here right next to each other.
I dug it...just 10 hours in with this thing that high tone found me a large white and yellow gold 14k ring, my first gold with my new tool but not my last.
I give all credit to this find to that nickel high tone...I am positive I would have never noticed this ring at the time without it.