Monty
Gold Member
- Jan 26, 2005
- 10,746
- 166
- Detector(s) used
- ACE 250, Garrett
- Primary Interest:
- All Treasure Hunting
I am soon going on a detecting trip where main items hunted are thought to be artifacts, perhaps ferrous based as well as copper and brass and if I'm lucky a little gold and/or silver. Although I have several detectors to choose from it occurred to me that I really need something that will go deep and not worry too much about discrimination. It seems to me that a PI detector would not be a handicap rather an ideal detector for that purpose. So, I did some dry land testing with my Sea Hunter II just to see what I might encounter.
Since the area to be hunted is several acres I will need to cover a lot of ground in the time I have allotted, so I assembled the Sea Hunter with the 14" coil. The Sea Hunter is quite heavy, not a serious consideration for submerged use, but very tiring on dry land. Therefore I rigged it for placing the power head on my belt, (one of several options with the Sea Hunter) rather than on the shaft, making the shaft and coil much lighter and easier to swing. The shaft was a little flexible with the big coil and tended to flop around a bit, annoying at most, but still workable.
I placed 3 targets on the ground and used a wooden golf tee painted blaze orange to keep track of them. The first target was an old oxidized shell casing I picked up somewhere. My second target was a clad quarter. The 3rd target was a 425 gr. 45/70 lead bullet. The fourth target was a large mans 10k gold ring. The fifth was a 2" steel screw. And the last target was an aluminum pulltab. I set the threshold to where I could just barely hear a hum in the background with discriminationset at zero. The mode was set at Standard Trash Elimination. (Contrary to what some have posted, the Sea Hunter, even though a PI unit does have a discrimination feature). Wit the setttings used all the targets were readily picked up and pinpointed. With the 14" coil the pinpoint is just behind the toe of the big coil. With the smaller 10 1/2" coil the pinpoint location is right in the middle of the coil. The problem present now is that the Sea Hunter doesn't have a VMI meter or a depth meter, and it goes very deep. So, in the field you would just have to know you had a metallic target and dig until you find it or give up! You can pretty well determine the size and.or shape of a target by working the tip of the coil around it's edges. (IE: an aluminum can for instance). Not too much of a handicap as artifacts can be quite large. I guess one has to set a predetermined drop dead limit on depth. Depending on the condition and composition of the soil I probably won't exceed a foot. Just my personal preference.
Next I wanted to test the discrimination feature, in particular to discriminate out the pulltab without losing my gold signal if possible. Following the instructions in the manual, I bumped the coil over the pull tab and slowly turned the discrimination adjustment up from zero until the pull tab tone disappeared. The adjustment knob ranges from zero to 9 and the pulltab tone disappeared at approximately 4.5. No change in the threshold was needed. I then took the coil and ran it over each of the remaining targets in turn to see if I had inadvertently lost them in the process. Every one of the targets toned in loud and clear except the pulltab. I was especially interested in the gold ring and it was an excellent quality tone.
Unfortunately I forgot to test a silver coin or item of jewelry, but I will test it soon and update the evaluation. Pulltabs were my major concern and you know what a nuisance they are when working an all metal mode. Indications in this static test would seem to point to the ability to discriminate out pulltabs and still pick up the desirable targets. On the other hand I don't know if old weathered pulltabs in the ground will be discriminated out. They do show up somewhat different on my other detectors. And I suppose I could miss some small aluminum targets, but that shouldn't be a problem when digging older artifacts. The proof of the pudding will be the Chisholm Trail hunt and I will report my field experiences when I return. Monty
Since the area to be hunted is several acres I will need to cover a lot of ground in the time I have allotted, so I assembled the Sea Hunter with the 14" coil. The Sea Hunter is quite heavy, not a serious consideration for submerged use, but very tiring on dry land. Therefore I rigged it for placing the power head on my belt, (one of several options with the Sea Hunter) rather than on the shaft, making the shaft and coil much lighter and easier to swing. The shaft was a little flexible with the big coil and tended to flop around a bit, annoying at most, but still workable.
I placed 3 targets on the ground and used a wooden golf tee painted blaze orange to keep track of them. The first target was an old oxidized shell casing I picked up somewhere. My second target was a clad quarter. The 3rd target was a 425 gr. 45/70 lead bullet. The fourth target was a large mans 10k gold ring. The fifth was a 2" steel screw. And the last target was an aluminum pulltab. I set the threshold to where I could just barely hear a hum in the background with discriminationset at zero. The mode was set at Standard Trash Elimination. (Contrary to what some have posted, the Sea Hunter, even though a PI unit does have a discrimination feature). Wit the setttings used all the targets were readily picked up and pinpointed. With the 14" coil the pinpoint is just behind the toe of the big coil. With the smaller 10 1/2" coil the pinpoint location is right in the middle of the coil. The problem present now is that the Sea Hunter doesn't have a VMI meter or a depth meter, and it goes very deep. So, in the field you would just have to know you had a metallic target and dig until you find it or give up! You can pretty well determine the size and.or shape of a target by working the tip of the coil around it's edges. (IE: an aluminum can for instance). Not too much of a handicap as artifacts can be quite large. I guess one has to set a predetermined drop dead limit on depth. Depending on the condition and composition of the soil I probably won't exceed a foot. Just my personal preference.
Next I wanted to test the discrimination feature, in particular to discriminate out the pulltab without losing my gold signal if possible. Following the instructions in the manual, I bumped the coil over the pull tab and slowly turned the discrimination adjustment up from zero until the pull tab tone disappeared. The adjustment knob ranges from zero to 9 and the pulltab tone disappeared at approximately 4.5. No change in the threshold was needed. I then took the coil and ran it over each of the remaining targets in turn to see if I had inadvertently lost them in the process. Every one of the targets toned in loud and clear except the pulltab. I was especially interested in the gold ring and it was an excellent quality tone.
Unfortunately I forgot to test a silver coin or item of jewelry, but I will test it soon and update the evaluation. Pulltabs were my major concern and you know what a nuisance they are when working an all metal mode. Indications in this static test would seem to point to the ability to discriminate out pulltabs and still pick up the desirable targets. On the other hand I don't know if old weathered pulltabs in the ground will be discriminated out. They do show up somewhat different on my other detectors. And I suppose I could miss some small aluminum targets, but that shouldn't be a problem when digging older artifacts. The proof of the pudding will be the Chisholm Trail hunt and I will report my field experiences when I return. Monty
M 
nty
