5/17/15 Report - New $10,000 Plus Minelab Detector. Little Things Can Mean A Lot. Sharing Photos Made With GPS Enabled Devices

Written by the TreasureGuide for the exclusive use of treasurebeachesrport.BlogSpot.com.

Minelab GPZ 7000 Detector

Here is a picture of the new Minelab GPZ 7000 to be launched tomorrow, Feb. 18.   Preorders are being accepted.  The retail price is around $12,000.   I've seen them offered for $9,999.

It is a gold detector and supposed to be 40% deeper than the GPX 5000.

 The stem and body assembly look a bit like the Garrett ATX.




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One of the things that it took a long time for me to learn, and that I'm actually still learning, is that little things can make a big difference.  I was noticing just the other day how much difference a slight tilt in the coil can have.  I was using a powerful detector and a slight tilt sometimes made a big difference in signal strength.  That also means a difference in ability to detect deep or small targets.

Mostly what I've been noticing is the big difference made by changes in settings.  It really surprised me how much difference the threshold setting can make - not just on one detector either, but mostly pulse induction detectors. 

Some people simply adjust the threshold for comfort.  Some like the threshold silent while others like it louder.  If you do a test (I've done many) you'll see that the threshold setting can make a huge difference.  It won't necessarily make you miss the most obvious targets, but it can make it difficult to hear perfectly good smaller or deep targets. 

In my tests, having the threshold either too quiet or too loud, resulted in a surprising reduction in signal strength and losing a good number or signals altogether.   I would never have guessed how much difference it would make, but I tested it and found out for sure.

For many years I went out and set the settings to what I was accustomed to using or what seemed to work.  After extensive testing, I am now much more careful about my settings.  You can have a very good detector, but use it in a manner that makes it much less effective.  I now adjust my detector differently at different beaches and different parts of a beach, depending upon a variety of factors.

You can start by using the factory presets, what the instruction manuals suggests or what someone tells you, but if you want the best performance that isn't enough.

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If you use an iPhone or GPS enabled camera you should be aware that when you upload a photo from such a camera that you could be passing along additional data.  You could be unwittingly posting the location where the photo was taken, and possibly your name and other information stored with the picture.

You don't have to worry about the GPS data being included if your camera is not GPS enabled. 

If you use an iPhone to take your pictures, you can remove data that you don't' want to share before posting a photo.  Don't worry it is relatively easy.  I mentioned this before but I received a question about it so thought I'd post more information.

First, here is a general article about that.

http://www.fieldtechnologies.com/stop-gps-data-recorded-in-photos-from-revealing-where-you-live/

And here are instructions telling how to delete data from iPhone pictures before you send them or post them.

http://netsecurity.about.com/od/iphoneipodtouchapps/a/How-To-Remove-Geotags-From-Pictures-Taken-On-Your-Iphone.htm

You can check for data associate with pictures when using Windows 8 by right clicking on the photo, and going to "Properties" and then "Details."  You can then select to remove data if you wish.

I usually snip the pictures that I receive before posting them so the extra data is removed.   But if you want to make sure not to include extra data with your pictures or your own posts, you can follow the above instructions.

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It is good advice to slow down when metal detecting.  It might also be a good idea to slow down when driving.  I've seen some terrible driving lately and some bad accidents.  It isn't worth it.  Arrive alive!

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On the Treasure Coast the wind this morning was from the South.  In the afternoon it was coming from the West.  Expect a westerly wind for a couple of days.

There was a good negative tide today combined with a calm surf.   That is a good time to check the low tide area.

Happy hunting,
TreasureGuide@Comcast.net

6/2/14 Report - UPDATED. Metal Detecting in Black Sand, Salt Sand, and Noisy Environments, Gold Rings From Fresh Water Lake, and Increasing Surf

Written by the treasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.

Gold Ring Found by Robert H.
Photo submitted by Robert H.

On the Treasure Coast the wind has increased and the surf has increased as well.  We'll have to see what that does.  I don't like the angle right now.  I expect the waves to be too much from the East.

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UPDATE:  I went to the beach this afternoon after high tide.  I looked at about 8 different spots along a stretch of just over twenty miles.
I didn't see any erosion except for some little six inch cuts at the best of all the spots (not counting Fort Pierce South Jetty Park where the new sand has washed away to create a six plus foot cut already). 

Below are pictures of two beaches that I saw. 

Jensen beach had deteriorated since I last showed it.  Notice the sea weed.  That is a bad indicator.

And also shown below is the best of the natural beaches.  Still nothing but six inch cuts.

Jensen Beach Just After High Tide Today.

The Only Cuts I Found on South Hutchinson Island Other Than At South Jetty Park.

It seems I was right about the angle of the wind and waves.  The waves were a good four to six feet but the angles were wrong and the beach detecting conditions remain poor.

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Robert H. detected a fresh water lake close to his home and found three small gold rings and a pendant. 

Above is shown one of the gold rings.  It is a very common type.  If you've been detecting very long you've probably found more than one of these.

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The signal you get from your metal detector even if it is a good signal, always occurs in a background of noise.  Noise can keep you from hearing a signal, and therefore cuts down the effective depth that you can detect targets.  Generally speaking, the more noise there is, the more good signals you will miss.

Signal detection theory was developed during World War II when they were developing radar systems and trying to identify blips on a screen indicating the presence of planes.

We all know that you don't have to talk so loud when you are in a quiet room with one other person, and you have to talk much louder to be heard and understood in a noisy room.  That is a simple illustration of the signal in noise problem.

There are a variety of sources of noise when you are detecting.  Some are external, such as wind and the noise of waves breaking.  Some internal, such as tinnitus (that ringing sound you might hear in your ears, and even distracted thoughts.  And some noise come from your detector and the ear phones, such as the signals caused by black sand or minerals, or static in the ear phones caused by various things such as lightening or power lines or nearby metal detectors.

When you do an air test some sources of noise are eliminated or minimized and the noise level can be relatively low.  That results in unnatural results, sometimes better than what you would expect in the field.  In an air test, however, the results can also be worse than what you would get in the field.

Usually there is little difficulty in detecting large shallow targets that create a loud distinct signal, however, when you are trying to detect smaller or deeper targets that give a more faint signal, many of those signals can easily get lost in the noise.

Some detectors give very steady or stable threshold sounds.  That is the sound you hear when the detector is not detecting a target.  Others have a rough or unstable threshold.  An unstable threshold is a source of noise that can cause you to miss perfectly good signals and targets.

If you can adjust your threshold so that it is more steady, you might increase the probability of hearing good signals.  I say "might" because there are other factors that must be taken into account.

If you just increase the volume you will be increasing the loudness of the good signals, but would also be increasing the noise level.  That will not necessarily help you hear the more subtle signals, which can still get lost in the noise.

Here is a key point.  Lowering the threshold level too far to either eliminate the threshold or even to create a very stable threshold is not always a good thing to do.  The threshold level that is best for you will be determined by both your detector and your own operating characteristics.

When you lower the threshold too much, besides eliminating a lot of the noise, you can also lose a lot of the good signals. 

I personally run my detector very sensitive and fairly loud.  I hear the salt mineralization and other noise.   That doesn't bother me much, because I can usually identify those sources and distinguish those sounds from the good signals. 

Since we always operate in a more or less noisy environment, you should be aware that you are always attempting to discriminate between good signals and noise (bad signals.)    Sometimes that is relatively easy and sometimes more difficult.  One good thing to do is make any adjustments you can that will help  reduce the noise to signal ratio, without losing much good information.  That includes changing detector settings, headphone adjustments, and even your mental state.

If you hunt in all-metals or pin-point mode, you will hear a lot of things, many of which are not good targets.  You might, for example, hear concentrations of black sand or salt mineralization.  I'm talking about VLF detectors here.  Some people have a lot of trouble with that.  They think they can't hunt in black sand or salt areas without decreasing sensitivity.  They complain about their detector "falsing."  I don't have much trouble with that.  I generally run my detector the same over black sand as over non-magnetic sand, and over salt mineralized sand as over dry sand.  I hear those effects, but am not bothered by them because I know what they are and can distinguish between those effects and signals produced by targets.   I almost never decrease my sensitivity settings.   I really can't remember having done that.

If you are working over layers of black sand for example, your detector will respond to the black sand.  I say it sounds like a twang.  Smooth undisturbed layers will create a gradual sound, while a footprint or distinct edge in the black sand will sound more like a target.

Watch as you detect these things and you will see what it is that your detector is responding to.

If there is a coin in the black sand you will have a lot of noise but you will still be able to identify good signals.  Coins in black sand will cause signals that are more distinct than the twang of smooth black sand. 

Don't try to avoid all noise.  I've heard very experienced detectorists using very high-end detectors complain that they could not detect in black sand.  I used the same type of detector and detected in black sand every time I saw it and didn't make any adjustments to my settings at all to adjust for the black sand.  I simply listen to the sounds made by the black sand, but can distinguish other sounds created by targets in the black sand too.

The same thing goes for wet salt sand.  Where the salt water has just come up and stopped and then receded, at that edge, you might get a false signal.   Many times you will be able to see the edge that you are detecting. (Anther reason to keep your eyes open while detecting.)

That doesn't bother me.  I know what is creating the signal (noise in this case), and it doesn't bother me at all.  That is part of getting to know your detector.

If you learn to understand your detector and what it is telling you, you won't be bothered by noises like this.  In fact when you understand what it is, the noise becomes information. 

You might be surprised by the types of environments you will be able to detect when you learn how.

Don't try to avoid all noise.  Some noise is actually information when you learn what it is.

Don't be deterred by some falsing.   Try to identify the cause the falsing, which might not be falsing at all.


I'll be watching to see how the beach develops.


Happy hunting,
TreasureGuide@comcast.net