If those coils run well on it, you just about have your bases covered. Make sure you can run your coils in "Fine" "Tiny" gain up to max, check that the detector is still responding in ch1 and ch2.(just purely a test, you most likely won't be able to detect like this) If either of the channels go quiet, then the coil is most likely not suited to the machine. Some are, some aren't.
One coil that is proving to be a good all rounder is the 12" Evolution coil. Very sensitive on the smalls and still punches deep. However for the really small bits <0.2g I still think the Sadie has the edge, but over .2 and the evo is in an element of it's own.
The settings used below were:
Timing: General
Frequency: Tiny
Channel select: Both
Gain: Around 3'oclock or more depending on ground noise and emi.
The areas targeted were pipeclay heaps and wash. The above settings most likely won't work on highly mineralised/variable ground. You would at minimum need to back the gain off.
Over Easter I went back to a spot that I have been over many times in the past with different coils, different detectors, settings etc. It's a bit like my proving ground. While I didn't find any gold this time round, I did manage to find a button on one heap that I have been over that many times it is not funny and it was a very obvious signal. And another heap I had been over just as many times gave up a belt buckle, once again, quite an obvious signal. I then moved on to another nearby spot that I had always driven past thinking I should have a crack in there one day. There was a bunch of wash(practically no mineralisation in it) beside the creek, brought down the hill from the diggings for processing. Started checking it out, noticed a recentish dig hole, so checked out the spot, cause you just never know what others leave behind
Well, there was nothing left, so continued on my way. About a meter and a half away I got this nice gentle whisper from a target. Scratched around and took about an inch off, still there. Eventually after digging down approximately 14" the target popped out. I was thinking, bugger this is going to be another rusty piece of poo. Anyway, sifting though the pile I had the target in hand. Was a nice 1.16 grammer
In disbelief of the depth it came from, I sat it back in the bottom of the hole and waved the detector over it, sure enough, I could still hear it!
And the hole it came from.
So, I got all excited, started detecting very thoroughly around the spot, when I got a signal under a fallen tree. Shifted the tree out of the road, dug down to be greeted by a bit of rusty steel. And then another and another! I managed to weave my way in past all the junk to find the nugget! Anyway, stayed in the spot and checked out the diggings up on the side of the hill and found a few small bits.