You would need and Etrac or CTX 3030 for more exact coin target ID if you could get them to stop masking in the thick targets you described. Otherwise, that sounds like an amazing place. First you could attach a pretty strong magnet to a wooden broom, rake, pick, axe or shovel handle (with or without the rake or shovel attached) and pick up most of the surface tin and iron in the area you are gridding and fill a bucket pretty quick without a lot of bending over.
You can use any Park or Field mode you want. For me, in a new place I would probably pick Field 1 multi to start. You have three choices. Listen to some iron while you detect. Listen to the threshold tone null (go silent) over iron targets and leave the accepted targets sounding good while any falsing iron in the mid teens to low 20s will break up a bit if the iron is not too big and then use the horseshoe button to double check for iron confirmation. Or, totally cherry pick.
So, say you want to hear some iron. Personally, I would hunt with nothing rejected if possible or at least -5 to +40 accepted so you will hear most of the iron. I would go into settings/volume, hold down the settings button until you see "t1" and set t1 to 1 so that the iron volume will be on the lowest audible volume level. Leave threshold on 0. Use 2 tones. I don't personally like the really low default iron grunt sound so I like to raise it up to setting 5 or 6 in thick iron. So if you want to do that hold down the settings button while at 2 tones until you see "t1" and raise t1 to 5 or 6. The medium tone created for that iron tone setting is a lot less fatiguing in my opinion. Leave accept/reject alone if you can. Set FE "iron bias" on 0 or 1 so the Nox will not mask good targets while trying to eliminate iron. Leave recovery speed on 3. Since you are just trying to get the easy stuff I would not put the sensitivity over 15 or so if you are doing a grid or just scouting the near surface layer of targets. Lead, gold, brass, bronze, copper and coin targets down to about 8" will really hit hard if they aren't masked too badly and will have very clear tones hopefully. If you ground balance carefully you can also use the Pinpoint function or just raise the coil to size targets. The depth meter is pretty good on coin sized targets too. On big stuff and little stuff it is fairly useless until you get used to it. If you keep your sensitivity down around 15 or a bit lower on the first pass it should also not sound off on every fly speck piece of metal.
If you want to hunt with an audible threshold tone you can set threshold on 4 to 7, 2 tones, FE 0 or 1, recovery speed 3 and leave Field 1 discrimination on the preset +2 to +40 accepted. When you hear the threshold null or a crackly teens to mid 20s target, check for iron with the horseshoe button.
If you want to try and cherry pick just the easy silver coins (forget the nickels, gold and indian heads in this case since they will all fall in the lead/brass/copper range) you can reject all the way up to 22 and leave 23 to 38 accepted. Reject 39 and 40 for iron wrap around or not....... You will still get some falsing bigger iron and tin (check with the horseshoe button) but the good coin targets should sound really nice. Keep the sensitivity around 15 or less on your first few passes of the gridded area. You could have default Park 1 set up for cherry picking (make sure to set iron bias on 0 or 1) and Field 1 set up for hearing iron or threshold tone and switch when you need to.
Just a few things I've tried and they worked pretty well.
good luck,
Jeff
