What about the effect of ground conditions and electrical noise on semi-auto? In one park I hunt the Explorer is 100% stable running sens 30 manual, it stands to reason that semi-auto sens 32 would also run about 30 and so you find deep targets. But what happens when conditions are not as favorable? That's what I tested over the past few hunts. In tougher spots where I can run sens 25-26 manual with medium instability semi-auto backed off the sens to like 16. It was perfectly stable but at what cost? How many deep coins or on edge coins will you find at sens 16 (half power)?
Is semi-auto better for someone just starting? Maybe but I think if you are going to run semi-auto sens you should switch to manual, back off the sens until the machine is just as stable and find out exactly how much sens semi-auto is running. If its around 16 leave it in manual and boost it back up to a workable level.
Newbies...I would spare them my newbie experience. I read the books, ran stable semi-auto with the newbie settings and found hundreds of clad the first two months. In my opinion this was a waste of time, worse in fact because after digging hundreds of clad and a bag full of trash if a target didn't hit right on the money I kept walking. That's what digging shallow targets teaches you. After two months I still had no idea what good deep targets sounded like or how they react on the smartfind screen. Many good deep targets actually hit on the screen where shallow trash targets hit. They don't sound the same but newbies tend to rely on that smartfind screen.
Newbie Plan - First Weeks
Iron mask -8, gain 7, sounds ferrous, sens manual and adjust until its just a bit unstable then back it off a notch so that when you scan a target the cross hairs don't jump around. Max var and vol. Pick a minimum depth for the site you are at. Around here its about 6 inches, not many old coins less than that so dig everything 6 plus inches and ignore everything less than 6, except quarter hits of course. Don't pass up those 8-10 inch signals that look like junk, you never know what you will find at that depth, lots of fun relics and jewelry. Adjust your minimum depth as needed, if you start with 5 but you are digging a lot of trash, go to 6.
Pay attention to the sound before you dig, then if you get a coin or trash item, make a mental note of how it sounded. Tabs broken off pull tabs and often folded are nortorious for giving a false depth reading. They will read 8 inches but are really more like 4, if you can pinpoint them down to a 1-2 inch circle its probably a tab. Cut a shallow plug and check the hole, they also have a unique sound which you learn. Small bits of foil do the same thing, they give a false depth reading. Rusted bottle caps are tough, they sound great with ferrous sounds, but a lot of neat relics hit in the same area of the screen, the bottle caps tend to have a baloon popping kind of sound, you dig a few of those and you learn quick. Also, the more rusted, the better they tend to sound and very rusted shallow bottle caps give a false depth reading.
Take mental notes of nails you dig, the sound, the difficulty in pinpointing, how often they were in the side of your plug, how it was work trying to get them to give a high pitch from both directions and you probably had to adjust your sweep speed to get a high pitch from the difficult direction. Don't let iron spook you though, if you get a high pitch silver like ring from two directions mixed with iron, without having to mess with your sweep speed, there is a fair chance you have silver next to iron. High iron pitch falses sound different from high silver/coin hits.
When you get an iffy target with nulls around back the iron mask off to -16 and sweep again, without any nulls getting in the way its easier to see what you got. Turn the iron mask back up afterwards, you will go crazy trying to start off in iron mask -16.
Iron Mask, as you grow comfortable back the iron mask off to -10, then -12, and spend some time checking targets at iron mask -16. I hunt almost always at -16 these days. A time saving trick is to setup a smartfind screen to imitate iron mask -8, while the iron mask is set to -16, this way you can switch back and forth quickly. Also, you may want to disc out crowncaps as they can be a pain running ferrous sounds in trashy areas, this gives you a imitation iron mask -8 screen with crown caps disc'd out also.
Learn to dig the deep ones, find some nice old coins, relics, jewelry, and the shallow targets become childs play.
