Explorer DARK ARTS Lesson #49 (for Syd BC)

[Charles (Upstate NY)]

Charles, that's a great post. I always use the smart screen and I'm getting better with the tones. I've found that the most difficult step is getting the right sensitivity while working in close to iron trash. A small step up or down can change everything. How do you get it just right? Thanks...Syd

Beyond adjusting the machine for reasonably stable operation why adjust sensitivity at all? I only adjust sensitivity due to mineralized soil or AC power interference so the cursor is not jumping around too much. I see no reason to dial back sensitivity in iron because of iron. If its an iron hell hole I'd more likely go to an 8" coil and leave my sensitivity alone. Another good trick with iron...when the ground is wet, sopping wet even, go home and return after the ground has dried out. Dry soil tells iron to shut up.

Here's a dark arts info nugget...the Explorer transmits at maximum power no matter what your settings are sensitivity or otherwise. So think about this, no matter how you setup your machine its going to transmit at max power out the coil. Therefore you are going to receive back the strongest possible signal from the coil. So what do all these settings really do? They take the entire signal from the coil and start carving it up. You start with 100% and via settings take away the parts you want to get rid of. Its an important concept knowing you can't actually reduce the strength of the signal induced into targets with settings. Settings are your carving tools, you start with the whole signal, the 100% of what the coil gives you and you start carving off the parts you don't want. With settings you can carve off some of the ground (soil) part of the signal. You can carve off AC power interference. You can carve off rusty bottle caps or iron. What's left is what you hear and what you see on the screen. In carving you may inadvertently carve off the target signal via discrimination or reducing your sensitivity too low or running recover too fast or too slow. But just know you begin with 100% from the coil, your settings in one way or another simply carve up this signal. Hope this helps.

 

[stasys]

True, detector is all the time on max transmitting power,but with lower sensitivity detector works a bit different, on all Explorers I can feel this and this is probably because programing and very old processor. Transmitting and receiving its not equal.

 

[Charles (Upstate NY)]

stasys with an oscilloscope connected to the coil receive winding there is no change when sensitivity is raised or lowered. Explorer coils are dumb, its nothing but copper wire, shielding paint, and epoxy there are no electronics in the coil.

 

[Syd BC]

Thanks Charles, that's an interesting way or thinking about it. I'm using an Explorer SE with the Ultimate 13" coil. I like to use an open screen with a small amount of iron mask. I set the sensitivity to as high as possible from where I start detecting, then I adjust the sensitivity up or down depending on the amount of rusty trash, usually nails. I'm always watching that top line on the screen looking for silver, and I do alright, but dig my share of nails. I'm going to take your advice and leave the sensitivity alone. In fact I might be running it too hot as the cursor does jump around a lot. If the Explorer transmits maximum power at all times then I should be able to reduce sensitivity without loss of depth. I'm re-working some old parks where there are some good finds, but they are deep, and hiding in the trash. Thanks for all your advice. I've read your original post many times...Syd

 

[Chris(SoCenWI)]

Think of it like Grandma's hearing aid. If she turns it way down she can't hear a thing, or maybe just the really loud noises; but all the sounds around her are still transmitting at full power. Turning down the sensitivity on your machine causes it to not respond to weaker signals. The amount of ambient electrical magnetic interference is the main factor on where you set your sensitivity. I think one of the Fisher engineers said if there were no EMI detectors wouldn't even have a sensitivity control.

Out in the country or in large parks away from power lines I can usually run my sensitivity almost maxed out. In town I can often only run at half of that. Guess where I find my older finds? Should be more in town, given the higher population density, but the amount of EMI keeps me from hearing the deepies. When they do road costruction and pull off few inches of top soil, different story. The coins are there; I often detect before and during a construction project, but generally can't get them before the soil is removed because of having to run at low sensitivities.

If you are turning down your sensitivity so you don't hear all the million nails and iron you are also not hearing deeper good targets.

 

[stasys]

Think of it like Grandma's hearing aid. If she turns it way down she can't hear a thing, or maybe just the really loud noises; but all the sounds around her are still transmitting at full power. Turning down the sensitivity on your machine causes it to not respond to weaker signals. The amount of ambient electrical magnetic interference is the main factor on where you set your sensitivity. I think one of the Fisher engineers said if there were no EMI detectors wouldn't even have a sensitivity control.

Out in the country or in large parks away from power lines I can usually run my sensitivity almost maxed out. In town I can often only run at half of that. Guess where I find my older finds? Should be more in town, given the higher population density, but the amount of EMI keeps me from hearing the deepies. When they do road costruction and pull off few inches of top soil, different story. The coins are there; I often detect before and during a construction project, but generally can't get them before the soil is removed because of having to run at low sensitivities.

If you are turning down your sensitivity so you don't hear all the million nails and iron you are also not hearing deeper good targets.

This is true, but in max sensitivity receiver works different in trash even more compare with a bit lower sensitivity. In explorers it was more clear. With lower sensitivity its easy to work in trash. I prefer to use lower sensitivity.

 

[Charles (Upstate NY)]

Lowering sensitivity WILL lose depth, period. The severity of loss varies (A LOT) depending on your local soil, iron, trash conditions AND the size of the target say dime vs large cent.

Guys its not like we dig 100 silver coins per outing so when you get a deeper promising target STOP, take that opportunity to play with your machine settings. See what improves the signal, see what degrades the signal, learn to tune your machine to the local conditions. In Upstate NY where I learned to use my Explorer even within a 3 mile radius parks varied in soil conditions, in some cases soil varied within the same park from average dirt, clay type muck that rotted coins, and sand which preserved them. When I first started doing this I was stunned how fast a deeper target signal degraded from good to broken to no longer there (in some soil/iron conditions) by lowering my sensitivity just a few points. 28 solid, 26 not as solid, 24 severely broken, 23 gone! The worse soil I have detected in was some red stuff in Virginia and the Pacific NW volcanic black sand laden soil in Oregon. Now at the other end of the scale is NJ beach sand, love that stuff extreme depth and will hit on tiny silver, I'm talking the crab claw clasps broke off a silver chain and tennis shoe lace grommets.

I have watched Joe Demarco STOP many times to fine tune new machines like the ETrac and CTX3030 in the field. Occasionally he and I would compare targets before digging, if his new fangled machines can match the best I can squeeze from an Explorer SE Pro that's saying something. There were a few times when I said dude, what's wrong with your machine and mocked him laughing but after some re-programming and tuning Joe would get his machine hitting has well on the target as my Explorer SE Pro.

So adjust to the conditions, don't get stuck in a rut thinking there's one ideal setup in all conditions but be careful of lowering sensitivity.

EDIT: IMPORTANT - When hunting deeper targets, say 5" plus keep this in mind...the Explorer absolutely HATES air space between the coil and the ground. I use that fact as a feature when confirming depth on deep targets, just a bit of air space and bam the target vanishes. I routinely see this when digging deeper targets as I try to dig a couple inches short of them to avoid gouging them with my digger. Example, I once had a target which turned out to be 2 IH and a seated dime stuck together. Solid signal about 7" down, I dug about a 5" plug and the target vanished, nothing when sweeping with the 11" coil. Went in with the X1 probe and it was screaming right dead center in my hole.

 

[Chris(SoCenWI)]

Good to see you posting again Charles,

I've long noticed the same about air space under the coil being a huge depth killer. If the grass is even slightly high the amount of old deepies I find goes WAY down. I've also noticed this effect is worse with smaller coils, my WOT seems to be less affected.

Any ideas of why? I'm guessing it screws up the ground tracking, wondering if this still happens on non mineralized beaches also.\

Chris

 

[michael NY]

Charles, thank you for this information, very insight full. My next outing with the my Explorer I plan on following your tips.

Michael