Have I gotten all I can out of my Xterra 70 - SW WA - NW OR

[flysar]

After talking with a few folks who hunt in the same WA/OR area I do they have confirmed what my 70 has told me, this is some tough mineralized soil for a VLF type machine.

Readers Digest summary;
- stock concentric coil, GB 11-13, sensitivity no higher than 15 without falsing, deepest good target 4"
- MF 10.5" DD coil, GB 15-19, sensitivity no higher than 19-20 without falsing, deepest good target 4-5"
- LF 6" "Digger Coil", GB 15-19, sensitivity no higher than 23 without falsing, deepest good target 4"
- State Park, (3) 1950's Homes, 1900's Homestead - approx 200 coins, 3 Wheats (oldest 1919 at 4"), silver heart pendant 1", 30's watch fob 3", and 200+ pieces of trash - bottle caps, tin foil, tabs, etc

Can't seem to break the 4 - 5" barrier on coins, maybe there aren't any but there is that nagging question in the back of my mind;
- Am I getting deep enough?
- Is there a better VLF, FBS, BBS, PI machine for my ground conditions without spending $1500 or more?
- Should I suspect my machine needs to be checked at the factory?

I am going to hunt with a guy that uses a Whites TDI SL in this type of ground so I'll see how a PI machine does. He's a park, school, homestead hunter so he understands the need to separate trash & iron.

Appreciate your thoughts.

 

[Old Longhair]

Unless you've played around with offsetting your GB, or given Prospector mode a whirl, you can't be sure that you've gotten all that you can from it.
By offsetting the GB you're telling the machine to treat the ground as being even hotter than it is, which may get you a little more.
In Prospector mode the Xterra operates "more like" a PI machine, and will get you more depth, as it was designed to work in highly mineralized gold fields. The only bummer about Prospector mode is that you lose the TID. but being able to "DISC out" iron to quite a degree makes it useful for finding good targets in otherwise un-huntable ground.

 

[flysar]

I can't offset my GB unless you mean manually adjusting my GB +/- from the auto setting?

I thought prospecting mode didn't get you any more depth just allowed the detector to run a little smoother in hot ground... Thanks for the tip I'll give it a shot.

 

[Old Longhair]

Yes, I mean offsetting in manual GB mode. If you had a 705 you could offset it in Tracking mode.

And the trick to greater depth with Prospector mode lies partly in the frequency chosen. It was intended for use with an HF coil on gold, but has been found to work well on high conductors when used in conjunction with lower frequencies which penetrate the ground better and get a better response.

 

[Digger]

- stock concentric coil, GB 11-13, sensitivity no higher than 15 without falsing, deepest good target 4"
- MF 10.5" DD coil, GB 15-19, sensitivity no higher than 19-20 without falsing, deepest good target 4-5"
- LF 6" "Digger Coil", GB 15-19, sensitivity no higher than 23 without falsing, deepest good target 4"
- State Park, (3) 1950's Homes, 1900's Homestead - approx 200 coins, 3 Wheats (oldest 1919 at 4"), silver heart pendant 1", 30's watch fob 3", and 200+ pieces of trash - bottle caps, tin foil, tabs, etc

Can't seem to break the 4 - 5" barrier on coins, maybe there aren't any but there is that nagging question in the back of my mind;
- Am I getting deep enough?
- Is there a better VLF, FBS, BBS, PI machine for my ground conditions without spending $1500 or more?
- Should I suspect my machine needs to be checked at the factory?

If you are getting a ground phase of 11-13 when using the stock 7.5 kHz concentric coil, then I wouldn't expect much depth from it. In fact, I'm surprised you were able to reach depths within an inch of the 10.5 inch DD. The unofficial "rule of thumb" that I've come up with is the number 28. If you can properly ground balance your X-70 or X-705, and get a ground phase number larger than 28, you will likely get good results with the concentric coils. However, as in your case, if the number is smaller than 28, you will be better served with a DD coil. To find out HOW mineralized your soil actually is, go to the FAQFAQ section and read the article that BarnacleBill posted about Measuring your ground mineralization. Here is the link... http://www.findmall.com/read.php?55,574329,574329#msg-574329

I am a bit surprised at the lack of depth using your 10.5 -inch DD at 7.5 kHz. Understanding that you are evaluating a substantial amount of soil, I would still have expected a bit more depth, considering you were hitting targets with the concentric at nearly the same depth.

I am not surprised with the results of the "Digger" coil, even though you were able to run with a substantially higher level of Sensitivity than the concentric. However, as stated in Coiltek's literature, the Coiltek coils are intended for use in areas with Low levels of mineralization. http://coiltekmanufacturing.com.au/x-terra-digger.html

Typically, HF coils will not hunt as deeply as lower freqs. But I have found the 6-inch Minelab DD does quite well in highly mineralized soil conditions. I certainly don't want to mislead you into thinking the 6-inch HF coil will be a depth monster. But in your situation, I think you will find it provides better results than the "Digger", due to frequency. And comparable (if not better) than the 10.5-inch DD, due to the volume of soil you are analyzing at any one time.

I've not found a reliable VLF that provides visual TID, audible target tones and notches, any better than the X-TERRA. If I were in your situation, I'd bury some coins at varying depths, in my backyard. I know freshly buried coins aren't the same as coins having been in the ground for generations. But you can still get a good comparison between coils, using the X-70. With that said, before I gave up on VLF units and break open the wallet for a PI, try using Prospecting mode as Old Longhair suggests. Although you will not have discrimination (other than some element of Iron Mask), and you will be hunting without TID, Prospecting mode will hunt deeper than Coin mode.

Are there coins deeper than 4 - 5 inches in the places you are hunting? Tough to say. I suggest you talk some more with those folks who are hunting your areas. See what they are finding. And if you get a chance, go hunting with one of them to make some comparisons between your X-TERRA and the detector they use.

JMHO HH Randy

 

[flysar]

I'm trying to find a xterra user in the area to do some comparisons with. If they had a 18.75 coil that would be a bonus so I could see how that fares without spending another $150 just to find out it doesn't give me any more depth.

I buried a silver 1/2 shortly after getting my 70 but was afraid of leaving it and not finding it again; I don't recall the results but I wasn't impressed but that was also with the concentric coil. I'll go bury some coins and report back.

I haven't abandoned my xterra yet just trying to get as much out of her as possible.

 

[Goodbaja]

I live here in Vancouver wa and can say I am having the issue as you. Most of my coin finds are no deeper than 5 inches at most. Even in my test garden buried last year quarters are a scrambled mess at 6 inches. Can barely hear dimes at 4 inches or deeper. They are scattered numbers too, bumping between -6 to 30s. Ground balance in the low numbers all the time, high numbers for me are in the 20s. Started with gold pack 10x5 great coil and covers ground fast but could get no deeper than 5 inches. I got tired of trashy sites so I got the 6in dd hf. I walked around my own yard and pulled out a bunch of dimes I missed with the elliptical. Not sure why I missed so many dimes, the yard was hit hard by the elliptical and is not trashy, but is highly mineralized.

On the quest to go deeper and stay in the cheap I decide to trade the elliptical for a stock concentric 7.5khz. Depth is increased a little and as others mention TIDs are more accurate. Sensitivity is turned down a bit from the 25-28 on dd coils, down to 20-25 on the concentric. Not finding a thing deeper in the old spots so that tells me not much deeper then the 6in dd hf and the 10x5hf. One thing to mention I like on a concentric is I don't even use pinpoint mode. Just wiggle the coil to the loudest to e and your above it. The center circle is 3 inches round and so is my plugger so its perfect.

I gave up on old silver coins after talking to people in a couple clubs and some local farmers. First off we don't have the east coast history. Coins were barely used out here in the early 1800s closer to the late 1800s is when more people traded with coins. It was mainly trappers and early hunters and they mainly traded for supplies, not coins. And the coins they had they would hide back then for winter months. When most farms and land plots were being given out it would be a days or two journey to store or mill so that would be the only time they would carry the coins for payment. Also farmers tell me the kids do NOT play with coins much back then. They knew the value of a dollar. 1910 most people made $400 a year.

So with that I started my quest for other items and have been doing quite well. I would like to try the "digger" coil but afraid the high mineralization will render it useless compared to the 6in hf dd. The 6in hf dd has netted me quite a few silver rings with a unmistakable tone if it gets above the ring or jewelry.

 

[flysar]

Goodbaja - tried to send you a Msg but the system won't let me. Check your system and send me a Pvt Msg maybe we could meet up compare results on your test garden... I will bring my extra coils. I'll be in the Portland area on Friday.

 

[Goodbaja]

Gime2469@hotmail.com is my email. Just joined, so not sure why can't pm.

 

[Mark in S.E. IA]

Goodbaja, first off since you are new you can't sent or get PM's for a week or two.

your depth problem can be one of a few things. First, the coins in your area might not be all that deep. Most old coins I find in my area id 4 to 6" deep with some places coins are up to 12" deep but not that often.

second since you say that your soil is high mineralized then I would say that a DD type coil would work a lot better for you. I use the 10.5 MF DD coil and just love it for my high mineralized soil a round here.

Third, to help you find the deep old coins it is best if you wear headphones and to keep your swing speed down to a 3 to 4 second speed and some times a lil slower.

I hope some of this will help you..

 

[Goodbaja]

Yes I have headphones. I have had my machine about 2 years and find tons of stuff. I tried the concentric and it seems to do ok even though it is highly mineralized. It's penetrating at about as deep as the elliptical which I know is not a depth monster. Also finding virgin territory to hunt is key if you really want to find silver around here but don't expect much. I have searched at least 10 sites and barely find clad.