Findmall.com
 
 






Garrett Users Forum


Welcome! Log In Register
Side Scan Technology. ?
Posted by: Dancer
Date: September 19, 2017 05:29AM
Would you give up a inch or two on depth for a extra amount of detection around the sides of your coil. For myself it would depend on where I'm hunting. It would be best (for me) hunting fresh drops at the beach. An inch or two extra around any coil would be great in some circumstances vs raw depth. Now maybe some have a coil already that's able to reach out and grab Coin sized targets. Ones I'm familiar with are sensitive to about the edge of the coil only. I imagine would be very useful in competition hunts too.

Re: Side Scan Technology. ?
Posted by: Gamma_Joe
Date: September 19, 2017 01:04PM
Suggestion: try a "target imaging" detector, like the GTI2500.

On most detectors (including the Garrett AT series and other makers' models), when you press your "pinpoint" button you get one piece of information: a target "depth" reading.

Like the user's guidebook says, that "depth" reading is accurate for "coin-sized" objects.

If it's larger than a coin, it shows as shallower. If it's smaller than a coin, it shows as deeper.

You can try looking at your coil as you sweep, to see some indication of the target's size ... but it's really not much more than guessing, especially if the target is large and deep.

The reason is: with only one Transmit coil and one Receive coil, and one set of electronics processing the signal, you have only one "cone-shaped" image in the ground. The display's depth accuracy is based on a coin-sized target being there.

With the imaging detectors (GTI2500) you get two kinds of target information: size and depth, both shown together.

You have one Transmit coil and two Receive coils, with two sets of electronics processing the signals. The detector is processing two separate "cone-shaped" images, one larger and the other smaller.

No, it isn't perfect. But it works, and it's good.

I've done side-by-side comparisons between my GTI2500 and several non-imaging machines. Targets have been coins, crushed beer cans, and bottle caps.

On the non-imaging machines, they can show up ... sometimes ... as "deep coins". You don't know until you dig ... which means, you're doing more digging, with a deeper hole, and pinpointing around in the hole, than what the display was showing.

On the GTI2500, if it says "coin size" at any depth, usually that's what it is. If it says "large and deep", that's what it is. Again, not perfect, but a heck of a lot better than what the non-imaging machines give.

If you're out for coins, you don't dig the deep large stuff unless you feel like it. If you're out for relics, there too it's good to get an approximation of the target size and depth before you dig. If it shows "large and deep" then it's maybe a good relic or a large coin spill.

The whole point is ... at least you have both kinds of information up front (the depth and the size), to help you decide.

I think it's good to have that choice. You don't keep looking back over your shoulder so much, still wondering about the spot you just left behind you. You have a better idea of what's there.

Best to try both types of detectors and compare them together in the field.

Humble opinion only, but I hope it's helpful.

Cheers,

Joe

Re: Side Scan Technology. ?
Posted by: Dancer
Date: September 19, 2017 02:47PM
Quote
Gamma_Joe
Suggestion: try a "target imaging" detector, like the GTI2500.

On most detectors (including the Garrett AT series and other makers' models), when you press your "pinpoint" button you get one piece of information: a target "depth" reading.

Like the user's guidebook says, that "depth" reading is accurate for "coin-sized" objects.

If it's larger than a coin, it shows as shallower. If it's smaller than a coin, it shows as deeper.

You can try looking at your coil as you sweep, to see some indication of the target's size ... but it's really not much more than guessing, especially if the target is large and deep.

The reason is: with only one Transmit coil and one Receive coil, and one set of electronics processing the signal, you have only one "cone-shaped" image in the ground. The display's depth accuracy is based on a coin-sized target being there.

With the imaging detectors (GTI2500) you get two kinds of target information: size and depth, both shown together.

You have one Transmit coil and two Receive coils, with two sets of electronics processing the signals. The detector is processing two separate "cone-shaped" images, one larger and the other smaller.

No, it isn't perfect. But it works, and it's good.

I've done side-by-side comparisons between my GTI2500 and several non-imaging machines. Targets have been coins, crushed beer cans, and bottle caps.

On the non-imaging machines, they can show up ... sometimes ... as "deep coins". You don't know until you dig ... which means, you're doing more digging, with a deeper hole, and pinpointing around in the hole, than what the display was showing.

On the GTI2500, if it says "coin size" at any depth, usually that's what it is. If it says "large and deep", that's what it is. Again, not perfect, but a heck of a lot better than what the non-imaging machines give.

If you're out for coins, you don't dig the deep large stuff unless you feel like it. If you're out for relics, there too it's good to get an approximation of the target size and depth before you dig. If it shows "large and deep" then it's maybe a good relic or a large coin spill.

The whole point is ... at least you have both kinds of information up front (the depth and the size), to help you decide.

I think it's good to have that choice. You don't keep looking back over your shoulder so much, still wondering about the spot you just left behind you. You have a better idea of what's there.

Best to try both types of detectors and compare them together in the field.

Humble opinion only, but I hope it's helpful.

Cheers,

Joe

Think I must have been unclear Joe. I hunted a1500 (Imaging)for 15 years. I'm talking about getting more power to the sides of the coil. Like in air testing for depth, but air testing for off the edges of the coil. So that when swinging down the beach your covering more area than the size of the coil. Maybe by a inch or two on a coin sized target. Most coils will detect a large metal target , but I'm talking coin/ jewelry hunting.

Re: Side Scan Technology. ?
Posted by: Gamma_Joe
Date: September 20, 2017 04:14PM
Hi Danny, I was thinking along the line of the imaging coil having two Receive windings ... The inner winding is seeing smaller targets, while at the same time, the outer winding is seeing targets in the area outside of the smaller one. Now I see that's not what you were looking for.

As far as I know the only detectors which gave a signal on something outside the coil's area were the old BFO ones. They would react to any metal you pushed at them at the side of the coil, not just around the center.

Re: Side Scan Technology. ?
Posted by: cherringtonsm
Date: September 30, 2017 11:07AM
Maybe I'm missing something here but my coils depending on how high my sensitivity is set will detect several inches around the perimeter of the coils. For example if my sensitivity is at max and I'm within 15" or so of a leg of a swing set or other metallic piece of playground equipment it will definitely sound off. I'm thinking if they will do that they should be detecting downwards to some degree as well.

Re: Side Scan Technology. ?
Posted by: Dancer
Date: October 03, 2017 06:39AM
Quote
cherringtonsm
Maybe I'm missing something here but my coils depending on how high my sensitivity is set will detect several inches around the perimeter of the coils. For example if my sensitivity is at max and I'm within 15" or so of a leg of a swing set or other metallic piece of playground equipment it will definitely sound off. I'm thinking if they will do that they should be detecting downwards to some degree as well.

Of course Cherrington, Were talking about coin sized targets. Try your test on a dime, for instance.

Sorry, only registered users may post in this forum.

Click here to login