Silver uMax Questions

[Dave Rishar]

I recently purchased one of these and am still trying to get the hang of it. As I'm pretty inexperienced with detecting in general, a few questions came up:

1. An area of reddish clay I detected several days ago had the poor Silver pinging and popping like mad, some of which sounded close to legitimate targets. I'm assuming that it's fairly mineralized. No amount of discrimination or sensitivity adjustment would shut it up. With care I could usually pick the real targets out of the chatter but it was not particularly easy. (Figuring out which targets were worth digging or not was another matter. ) Is this to be expected in areas with bad soil? Any tricks to cut out some of the noise?

2. Air tests revealed that discriminating above "Foil" basically discriminated out gold as well, yet at this setting I'm picking up almost everything metallic (even pieces of nails) and the iron's hitting more solidly than coins in some cases -- but not others. I'm starting to notice the subtle differences in tones but it seems that whenever I get it figured out, a rusty nail or fragment of a hinge "hits" just like a coin does, or vice versa. Am I doing something wrong or do I just need more practice? What causes this?

3. Is it possible to discriminate out small pieces of iron without losing the good stuff? What's a good setting to start with? I haven't had any luck at all with this yet.

 

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[khouse]

I'm receiving my first Tesoro on Monday. I can only give you advice in general. I have been detecting since 1984 and used a non metered detector for about 15 years.

To answer #1 You just have to reduce you sensitivity until your unit runs stable. Every place is different. I would start with the sens maxed out. Then slowly reduce it until it's quits being nervous, cracking and popping.

Answer for #2 Some small gold falls into iron. Nothing to do about that. Gold can be found from iron up through tabs depending on size.

Answer for #3 If your looking for gold disc out a small nail and dig the rest. Sometimes this gets pretty tiring depending on your site. The more time you have to hunt the less disc you can run. I have been guilty of discriminating everything below zinc if I only have like 30 minutes to hunt. But if I find some good targets I'll go back another time with reduced sensitivity.

 

[EasyMoney]

Dave.

#1

The soil you hunt in has a massive amount of iron ore in it, red clay or not. The entire Pac NW has extremely difficult soil to hunt in, with very few exceptions in some valley soils. Some soils will not even allow a PI to be used very effectively in our area. On the Western Washington coastline there is a beach area that is nothing but iron-laden black obsidian round beach rocks of varying sizes. The surf is so violent that entire beaches are constantly being tossed up to the utermost part of the bank. Most people in the eastern and southern USA do not understand this concept at all, they think that our soil is just about like theirs, with few differences.

Not true.

Here is a little trick we used 20-30 years ago. Back then we usually knew a bit more about how detectors worked than younger people do today;

You have a problem with too much sensitivity for the red clay soil you are searching in. The sensitivity needs to be reduced if you have already reduced it to the minimum and it still pops and makes unnecessary noises. Remember too, that your ground blance, (external, or internal, or automatic or manual), is nothing more than a rough discriminator, cancelling out iron in the soil as best as it can..

Duck tape a large steel body washer to top dead center of your searchcoil. If you use too large of a washer, the detector will have difficulites operating well, and the detection depth will be reduced dramatically. Try different sized steel washers. A too-small one will cause the detector to not be affected at all, and one too large will cause it to lose so much sensitivity that the detection depth can go as low as only 2 inches with some detectors. A washer 4" in diameter to as small as 1" in diameter will usually work, depending on how much gain is built into the Silver. Silver's do have quite a bit of gain built into them though, and you may have to try a larger size first.

The reason this works is because the detector has a set level of parameters that it runs on, with it's automatic GB. By putting the iron washer on the coil, it brings the operating level from a more positive voltage to a more negative voltage and it's already at work cancelling iron even before it senses the soil. Your detector sees the soil as just.... iron, just like it sees the steel washer as....iron.

The voltage amount stays the same though. In common terms, it begins to operate on the wrong side of the tracks, with still the same 357 mag searching cababilities. The Fisher 1270 and Tesoro Tejon with their inherent extreme high gain have these same two problems, but to an even greater extent. The Tejon is a near clone to the 1270, it having been modeled after it, and the 1270 is the more powerful (highest gain) of the two. This is why the Tejon can get 15-16" on a penny in the air, and the 1270 can get 18" on the same penny, in air. In bad soil though, both of those really suck, as do (most) high gain detectors without a good corrective slow capacitive discharge add-on. This is partly why high end Minelabs run with lower gain, to combat the bad soil, which they do quite well too I might add.

I have one detector that I can bring the sensitivity down from 15' air test to 5" air test by employing this method. Anything larger than a 3" steel washer nearly stops the detector from working completely though. This does not overdrive the detector, nor does it or will it heat up any circuitry, but it will cause you to chew up batteries a little quicker. There is no way this can harm your metal detector, and it's for free, save for the 59 cents for a washer or two.

Khouse answered # 2 and #3.

Good luck and HH

EasyMoney

 

[Dave Rishar]

A steel washer? I never would have thought of that. (As I don't understand the physics involved, I never would've thought of anything else either to be honest. )

You both have been extremely helpful. Thank you very much. I'll give it another go on Wednesday and see what shakes loose.

 

[EasyMoney]

You will have to treat every detector differently with this little trick.

#1
On my Compass XP Pro Plus the air depth on a penny is 12" max. If I tape a 1" washer to the coil TDC it will not affect anything at all. If I tape a 4" piece of round steel plate, it will cause the detector to go completely quiet, no signal at all, no matter which mode I'm in. If I tape a 2" instead, the sensitivity gets cut down to reading 8", and this is just about optimum for hunting in the worse trash I can find, even in an old junkyard.

#2
On my Compass Scanner R&C the air depth is 15" on the same penny. The same 2" steel washer cuts it down to 10" air depth - and consecutive resulting loss in sensitivity.

Detector #2 is running 2 more volts (6.6vdc, compared to 4.6vdc) on the sending end, and this means that the second detector is a real POWERHOUSE, but still can be regulated a bit anyway.

A White's DFX or MXT reads;

11"-12" on the same penny.
Fisher 1270 reads 17"
Tejon reads 16"
Explorer SE reads 11"-12"
cz-70 reads 12"

I wrote the air depths for reference only. The Compass R&C will outdo ALL of them in the ground here, by at least 20%. There are no equals here.

All but the Explorer can be regulated by shifting the null parameters this way. I wouldn't experiment with the Minelab though, it's not a real smart idea. Most other detectors are ok to try this with though.

 

[BuckleBoy]

Also, since you're saying that you get the same signal for nails as well as other items...make sure that the toggle switch on the machine is in "Disc Mode" rather than "All metal"

 

[JOE(USA)]

Dave,

I just saw your post and wanted to jump in to see if I could be of any help. All of what has been said so far is is good advice, here are a couple more suggestions:

1. Are you using headphones? The subtle differences in the target sounds are much easier to pick out with a good pair of headphones

2. Hunt a cleaner area. "Try not to hunt the high trash areas until you know your detector better. Stay in low trash areas to learn. Keep the sensitivity control turned down. No more than 1/2 way up. Slow sweep in higher trash areas. When you fast sweep in trash areas it's like standing around with 5 or 6 of your buddies and saying "O.K. now everybody talk at once"! Hard to understand what they are saying. Slow sweeping is like saying "O.K. mike you talk then let Andy talk" and so on, much easier to understand them right? I would recommend that you stick with the 8" coil for now but a smaller coil like the 5.75 widescan (double "D") would see less mineralization and do less bridging of multiple targets."

3. Remember to change your sweep angle. Your looking for repeatability, and the angle of attack between coil and target is important. This is specially true on unsymmetrical targets (like nails) and multiple targets (masking).

Joe

 

[Dave Rishar]

I did some swinging on the lawn closer to the house and it was a very different experience. The signals were clearer, there was no chatter, and the bottlecaps and pull tabs were much shinier. I think it's just that soil down there that was raising hell with my detector. I might take another shot at it when I've gained some experience but honestly, I wasn't really digging anything up down there that made it worth the hassle.

Thanks all for the suggestions.

 

[bass99]

Dave welcome,
I use a silver saber and live in Grays Harbor(Aberdeen). Did you notice if you were hunting near telephone lines and if you did were there junction boxes on the poles? Because that will play havoc every time. Just a thought.

Bass99

 

[Dave Rishar]

No phone lines in that area. It's kind of out in the middle of the woods.

I'll chalk it up to inexperience and terrible soil, but mostly inexperience. I hit an abandoned homestead today with lots of trash and "chatty" soil and had much better luck. The problem before was that I was simply counting on one setting to work for every target and I've stopped doing that since. I still dug up a few false alarms but for the most part, could tell the difference between targets worth digging and trash/heavy mineralization and by the end of the day, I even had an idea of how deep I'd have to dig. This thread was most helpful.

I'll get the hang of this eventually. Lots of odds and ends today but I'm happiest with the axes, and whatever that other thing is. (No, not the 9v, the other other thing.)

 

[olegoat]

the other thing is called a gernade-lol- at least that is what the one i bought was called, its for splitting wood,