Question about the Fisher F70 Numeric Target ID

Marlon Brando

Greenie
Oct 3, 2009
19
1
So I put on some rain gear today and went out and hit our town soccer field that use to be a corn field. I was scanning and I hit on an area that was bouncing between 86 - 91 on the numeric ID about 7 inches down. Based on my manual, that would leave me to believe that it's a coin. Here's my dilemma. The confidence indicator was only showing one bar. Does anyone out there think it's worth digging for?
 

limegoldconvertible68

Full Member
Mar 18, 2009
228
14
Illiniois
Detector(s) used
Fisher F70 with 11"DD coil, CZ-21 with 10" coil, Fisher 1265X
Primary Interest:
All Treasure Hunting
I honestly don't think its worth digging up the soccer field for this target. Its deep enough that its most likely something from its cornfield days which makes me guess its a large iron ring. Possibly something from a horse harness or some farm implement. Its been my experience that those kind of items register in the upper 80's to low 90's. Sure it could be a Morgan dollar but the odds are against it. If it is iron, I have noticed that rusted iron doesn't always pinpoint exactly so you will most likely dig a nasty crater looking for it and the next thing you know is they ban you from the site. The F70 pinpoint is dead on when its a coin. The depth reading on coins is very accurate also. When you dig just past the depth indicated and you still haven't retrieved a coin, 95% of the time I end up finding old rusted iron off in the side of my hole somewhere. Occasionally there is a deep coin close to being on edge in the side but not often.
 

OP
OP
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Marlon Brando

Greenie
Oct 3, 2009
19
1
Well limegold, you were right. I actually went out on Wednesday night because I couldn't stand it anymore and sure enough, just a scrap piece of metal about 8 inches down. Spot on.
 

Rusted_Iron

Bronze Member
May 25, 2006
1,682
87
Corrodedlargecentville
Detector(s) used
Tesoro
Primary Interest:
All Treasure Hunting
hey guys, how reliable is the numeric ID on the F70 at depth? Put another way, at what depth does it begin to taper off as far as reliability? It sounds like if you can call a target at 7+ inches, that's a good machine there.
 

George (MN)

Hero Member
May 16, 2005
829
98
I have a F70 & I planted a quarter down 6" & the ID went just about everywhere except iron! Would never have expected it to be a coin. The deepest coins I've dug are 5 1/4" for penny & 5" for dime, but I don't dig the ones that bounce down to pulltab or below. Guess maybe I should when they're deep.

My ground is horrible for consistent IDs unless the coins are very shallow. My F70 can only tell the difference between a nickel & a modern tab if they are on top of the ground. Most of the coins I get down 4"-5" will bounce from one denomination's range to another. Whenever it jumps between ID ranges the confidence bar goes down to 1 but these have mostly been coins.

Also, my F70 often claims the coins are deeper than they are. I'm guessing the minerals or whatever in the ground make the coin signals weaker so the detector "thinks" they're deeper, based on signal strength.

I'm not knocking the F70, as nearly every detector I've owned has this bounce in my difficult soil, to a greater or lesser degree. HH, George (MN)
 

limegoldconvertible68

Full Member
Mar 18, 2009
228
14
Illiniois
Detector(s) used
Fisher F70 with 11"DD coil, CZ-21 with 10" coil, Fisher 1265X
Primary Interest:
All Treasure Hunting
"how reliable is the numeric ID on the F70 at depth?"

So far my deepest coins have been 8" measured on a wheat penny and I have dug four separate silver dimes that measured over 7" deep. They ID'ed very nicely and I knew they were coins before I dug them. Those were all found with the stock coil. I just recently bought the 11"DD coil and I think it ID's better with this coil. I have pulled a lot of 6" coins and they all hit louder and ID'ed in a much tighter range with the new coil. I have hunted against Etracs and have yet to see a coin that I couldn't find. Maybe I am nuts but I think the F70 can compete very favorably against any machine out there........especially when you consider the price.


George, I can't believe the soil in MN is that tough. If all I could get was 4" or 5" deep I would feel cheated. What kind of sites are you hunting and how high can you get your sens and threshold before you get chatter?
 

Rusted_Iron

Bronze Member
May 25, 2006
1,682
87
Corrodedlargecentville
Detector(s) used
Tesoro
Primary Interest:
All Treasure Hunting
The F70 has different audio tones, yes? Past some point of depth, can you just rely on that instead of the numeric target ID? I would be surprised if the F70 couldn't hit on the bigger coins past 8 inches, though I guess it requires some playing around with the settings to get the best depth.
 

TexasDigger1

Sr. Member
May 31, 2008
355
3
Texas
Detector(s) used
Teknetic G2, Excal 2 1000, Garrett Sea Hunter II
I have found dimes with my F70 at a measured 7" with a good ID but the depth meter always says the coin is deeper, I just don't use the depth meter anymore, I like to go by the way it sounds, good machine. HH
 

DEK1

Tenderfoot
Jul 10, 2011
6
1
I think sound is the best means by which you should judge to dig or not dig a target. The fancy VDI meters and all are nice to look at but learn what it is your detector is telling you with it's tones and you will have much more success pulling out the good stuff.
 

pescadore

Hero Member
Mar 4, 2007
736
425
Schertz, TX
Detector(s) used
Nokta Simplex+
Primary Interest:
Metal Detecting
So I put on some rain gear today and went out and hit our town soccer field that use to be a corn field. I was scanning and I hit on an area that was bouncing between 86 - 91 on the numeric ID about 7 inches down. Based on my manual, that would leave me to believe that it's a coin. Here's my dilemma. The confidence indicator was only showing one bar. Does anyone out there think it's worth digging for?
The F70 has good Id and tones. I run mine in 4H tones and love the high tone on nickels. The F70 is very good on locking in on coin targets. Coin targets should not jump around more than 2 or maybe three numbers. Jumping from 85 to 91 at 7 inches would be something I normally would not dig. Mine will ID coins good at 8+ inches but I have good dirt in my area. I also can tell nickels from pulltabs with good accuracy by the solid tone and ID of 32 with it switching to 31 and back sometimes. If the ID jumps more than 2 or 3 mumbers you can pretty much call a tab or junk. The F70 is one of the better if not the best machines I have owned. I have had a lot of top end machines including the Etrac and Deus.
 

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