I need your guidance...

[coinsh00ter]

Here are the parameters...

I use an x70, I live in a central NJ town that was established pre revolutionary war. Just for background my three best finds in town are a NJ copper, a VA penny, and a US 1/2 dime. They were all found on private property that I had permission to hunt, and I didn't find much else on those properties ( a couple of mercs and wheaties), but nothing to write home about. I found these items when I was using a Sov or XLT, don't quite remember which one, but I am not a newbie.

Now for some back ground:

I am using a local park as my test site. This park shows up on the earliest maps shown on a previous post for my city, 1880 or so. At that time there was a homesite, and now there is the typical raised wood chip monkey gym. I hunt an area old timers have said was the hub of the area in the old days (pre 1950). I have found wheaties, at least 25 at 4-6 inches. This is over the last 10 years with various detectors. This is a park I go to to just pass time, I will always find clads near the new equipment. Using all metal, you could dig iron junk all day. I have never found silver! I have lived in my house for 14 years, and have been detecting for 10 years. On more than one occasion I have seen md'ers in this park, a couple of times a group, leading me to believe that to find older silver I would have to go deep. However, I could almost guarantee you that if I went out right now, I would find a least one wheatie.

Now for my questions/concern:

I decided to go out tonite for about an hour, using the 6" cc. I set the x70 at sens. 25, higher than I can usually run. Did a gb in all metal and started to detect, in all metal. The machine was chippier than I have ever run it in the past. I ran three tones, and tried to listen for faint tones and repeatable signals in the 30s. I was getting the bopping around, from -8 to 46, numbers I have never found anything but iron. I worked slow and got a semi repeatable 34, with a 5 arrow depth indicator. I pinpointed, and it did jump to negatives, but still popped back to numbers in the 30's. I then switched to prospect mode to outline the object, it gave an outline of a small item. Lets Dig!!!. 6 inches down I found a nice rusty bolt head facing up. I read posts with guys running sens. at 25-28, with an almost unstable machine to get the deep objects. How do you differentiate from deep iron???? I can say after using the x70 for about a month I am very satisfied with the performance, but the coins I have found always seem to give a nice repeatable tone, no matter what the depth. I have yet to find a coin listening for a faint tone. Everytime I get a decent repeatable faint tone, that I think may be a real deep (8 inches +), it either turns out to be very deep iron, or a small fleck of foil.

I guess I making this post because half of me is frustrated that I may not be getting the depth I desire, and frankly I won't be frustrated if I didn't read the posts of coins at 8-12".

Sorry for the rant.

Dave in NJ

 

[Grant]

I just got my X70 and I'm not banking on finding a coin at a foot+ ( I HOPE TO) just from experience with the High end PI units and VLF'S 8's I can see but a coin at over a foot. That would be the perfect setting at the optimal ground conditions even to reach that far Not calling anyone a liar but I doubt you'll see many people claiming coins over a foot in depth. again I'm not sure but if I find a coin with my 70 at a foot+ I'll be the first to write in.

 

[Neil]

Dave I find the medium freq coils do better on IDing iron and you wont get fooled as much by it using them.
Also, just play around with it and see what works best, try tracking for the GB(I like this alot in the wet sand at the ocean), do several noise cancels,
make sure your threshold isnt to high, try and center up on targets for the best possible ID and with practice you can size up a target in the disc modes without going to prospecting mode.

HH
Neil

 

[Digger]

I won't speak for anyone but myself. But in 36 years of coin shooting, I have never found a coin at 12 inches either. Very few have been over 9 inches deep. And I have had plenty of detectors capable of detecting to those depths. Part of that, no doubt, is because the part of the Country I live in was not settled until the mid 1850's. So I won't say it don't happen. I've just not had it happen to me. Now I have dug a hole over a foot deep, looking for the coin. When I can't find it, and can't get the digger in the hole to dig any deeper, I enlarge the hole. Eventually, I'll find the coin in the bottom of the hole. But I figure I got in a hurry pinpointing and simply missed my mark. When I was removing dirt from around the edges, (to allow me to make the hole deeper) it fell to the bottom and appears to have been deeper than it was. But again, that is just another of my theories.

Speaking of theories, if you've read this forum for very long, you know I post an occassional "theory" that I pull out of my ........hat. One was my circular (vs linear) discrimination theory and why iron is sometimes TID at +48. Another is the GB at 28, to determine whether to use a concentric or DD coil One that I have been tossing around in my head is how deep will my detector detect. Basically air vs dirt. My theory is that a detector/coil combination will not locate a silver coin deeper in dirt than it will in the air. Sure, you might find some iron targets deeper, due to the iron oxide permeating the adjacent soil. Copper and copper oxide to a far lesser degree. But silver coins just don't leach out in my soil. As such, I have convinced myself that I will not find a single silver coin deeper in the dirt around here than in airtests. To suport this theory, I consider that GBing a detector is similar to discrimination, in that setting the GB will discriminate out the negative effects of the ground. If that is true, then it seems to me that the more mineralization you have in your site, the more "discrimination" it will take (via GB) to compensate for that mineralization. And with most VLF detectors, the loss of depth is proportional to the amount of discrimination. Now I know that ground balancing a detector is not the same as advancing the discrimination. But in my mind, the impact (of mineralization) on depth is similar. That is why I believe that if your maximum depth on a single coin in the air is say 10 inches, you won't likely find it in the dirt at more than that. Never say never, as non-mineralized, wet soil may provide less resistance (than air) on the eddy currents being passed between the coils. But generally speaking, I can't see it happening in the real world. At least I haven't been witness to it.

As to the "faint" tones....... Maybe it is just symantics. But faint is not the word I use to describe the sound difference. Maybe "shorter tone duration". Or simply "more narrow". But I just don't hear faint tones. It either beeps or it don't. And darned if those narrow target signals aren't the deepest ones! JMHO Randy

 

[Jackpine Savage]

Hi Dave,

You mentioned that the 70 was "chippier" at sens 25, I'm not sure by that if you meant it was noisy or running fine?

You should try increasing the GB manually a number or two higher than the auto result to see if its runs smoother in your ground allowing a higher sens setting. Also, be sure to noise cancel freqently when changing locations around that park area.

If all else fails get you one of those 7.5 Khz DD coils everyone loves.

HH Tom

 

[RLOH]

Dave, I don't have near the time with the x70 as the guys responding to your post, but many of your questions apply to any detector. With any detector, a faint(narrow, small, repeatable) signal can be a very small item. I have had CZ's for many years and I spend hundreds of hours with them. I get a signal that is EXACTLY like a deep copper or silver coin that shows 8 plus inches deep on the meter, only to find a small piece of foil at four inches. I think the key to your question is a coin on most any detector will repeat somewhat, unless it is on the fringe of your detectors depth capabilities. I always dig these signals. I don't think you will find coins much past 6 inches consistantly with the 6 inch coil. I have a test garden and a six inch silver dime is the deepest coin I can get a decent signal with. I recently had Randy(Digger) explain the ground balance numbers. I have used my xterra 70 for about 35 hours or so and I have yet to have a number higher than 20 and most of the time it is between 12 and 15. I have not used the 9 inch 7.5 khz concentric coil only for a short test. I have used the 10.5 DD almost exclusively and even with the low ground balance numbers, I can run the sens at 27 -28 . I know some might think my depth claims are an exaggeration, but I find coins deep every time out. Deep, meaning 8 plus inches. I found two more wheats that deep yesterday. Yes, they were a small, narrow, faint signal. If people waited for a clear, concise, banger of a signal, they would not dig a deep coin and this pertains to any detector. One charateristic of all these deep coins is they will repeat from more than two angles even though the signal is small. I have found if you get a deep signal and when you check it from all angles and one of your angles gives an iron grunt, it is indeed rusty iron. After I realized this characteristic of the 70, I am lucky if I dig one or two pieces of rust a day. I purposely dug the first eight or ten of these iron signals that were mixed with faint high tones and figured out that this meant rusty iron. I suppose it could be a coin next to a rusty bolt. All of my findings were done with the DD 7.5 khz coil. Randy has found the 9 inch 3 khz coil responds differently to iron. I think I read that somewhere, so maybe he could help you in that area. Good luck and don't give up on this detector as it is too good of a machine! R.L.

 

[coinsh00ter]

I would not give up on the x70, it is a great machine. I have a 3khz coil coming. The area I am hunting is strewn with old iron, like many older sites in my area. I find the iron bounces from negatives to mid to upper forties. Thanks for the responses, especially what others consider "faint". My deeper finds have a nice clear "short" blip, that repeats.
Dave in NJ