Locating and pinpointing deep targets Coins that are 6 inches or deeper can be hard to find if you're in a hurry. You have to slow down and overlap the search path, just inch forward if you can. This can get boring in a hurry. But once you locate that first deep old coin, it would be a worthwhile thing to do. Sometimes you might get two coin signals 4-6(roughly) inches apart. One is shallow and one is deep. Try digging the shallow one first. That shallow coin may be on edge and is causing a secondary false coin signal that pinpoints as a deep target. I found this out one day by digging the deep coin signal and finding nothing. I then dug up the shallow coin and then the deep coin signal disappeared. It can also be two separate targets, but why not save your-self some frustration? A good coin signal will be repeatable from darn near any direction. When I get a good signal, I will turn and check the signal from 90 degrees to the first signal. If I can get any type of signal, then I know it's probably good, except for rusty nails. Coins on edge can read good in one direction but not at 90 degrees.
Often a false signal will occur in one direction, but not the other, or at the end of the swing. Extremely deep coins could probably do this. So it would be a good idea to see if you can get a signal in the pinpoint mode. (By both directions I mean left to right as you swing the coil in front of you.) Try digging a plug and see if the signal gets better, which would indicate a good target. If you are getting too many false signals try reducing the sensitivity or switching to a smaller coil in trashy areas. Place some coins on the ground and see how they sound from different heights and directions. This will help you to recognize what a repeatable signal is. Try pinpointing by lifting the coil in the air, high enough to where you can barely pick it up. In extremely trashy areas I sometimes have to pinpoint in the disc mode, or dig the surrounding trash first. I wouldn't be concerned about digging deep targets until you can recognize what a good repeatable signal is.
Extremely deep coins can cause the audio to stutter, but still lock on coins. I'm not sure if itís the depth or maybe the coin is on edge and deep but I encounter this only once in a great while. This is where you want to double check at 90 degrees. If you're not sure, then dig a plug and see if the audio improves.
I once got a coin signal at six inches but I couldnt get any pinpoint
signal.I believe the signal was detectable at 90 degrees.I checked out
my detector and it was working in all modes.(batteries were fine) After
analysing the signal several more times it was just too good to pass up.I
started to dig and checked with the pinpoint mode several times until I
reached about 5 inches.
Not much of a signal in the pinpoint mode yet.Finally at about six inches I pulled out a wheatback.I dont know if it was perfectly straight up and down or what.That was probably the weirdest signal I have dug. Sometimes even though a target may not pinpoint right, or at all, something says to DIG it!!
Rusty Nails on edge like to read as coins on the meter. It is a good idea to take some time and analyze the signal before digging. This can save a lot of frustration. These nail tips aren't foolproof, or should I say IRON proof? With experience you can reduce the number of them you dig. I've found that if a signal sounds suspicious or iffy, it's usually iron.A lot of the iron or other trash signals(false signals) can be ignored simply by listening to the audio signal! This takes some practice.But it can save a lot of frustrating digging. When I get a good coin signal, I will watch the meter as I scan back and forth. If just one time the needle drops to zinc and then goes back to coin, it is iron. I haven't found a coin in this situation yet so I can't say for sure that it isn't a coin. But dig a few and see for yourself. A deep, flat coin like a penny or dime should pinpoint as a small target where as an iron nail likes to run in one direction. Though, heh, heh, once in a while the signal will sound good, lock on coins, pinpoint small, and still be a rusty nail:( Say you get a good coin signal at 7 inches. You dig down 5-6 inches and all of a sudden the audio starts to skip. It should be an iron target the CZ is trying to disc out! Coins just sound good, sort of round -like, and you know it before digging them. I usually hunt with disc set on one. Then I'll turn it down to zero to see how much iron buzz I get. But some coins will give you a low iron buzz, so don't use this exclusively as an indication to dig or not. When in doubt, DIG!!!
The following was taken from the Fisher World Treasure News 1996-97.