Target Separation on newer detectors vs old

[scdetector]

This has puzzled me for years! I have a piece of paper with a quarter taped on it with multiple trash items I’ve used for years. I have tried a Nokta, Apex, Vanquish 340, 440, 540 along with the Ace series, a F-70, F-22 along with several others and none can pick out this quarter except my Tesoro detectors. I have tried various settings on the other detectors and they are silent except in all metal mode of course. I thought possibly EMF so I ruled that out. It’s like the quarter is masked by the trash. My 540 with the V-8 coil passes over it in coin mode and it May beep depending on the angle but the target ID is everywhere. I have a U-Max, two Cibolas and a Vaquero that will give a solid beep on the quarter, I’ve tried replacing the quarter with a penny with the Tesoro’s and it hits the penny, if I turn the discrimination to full it will not detect the penny. So what’s up with the newer digital detectors?

 

[Carl-NC]

Are you using DD or concentric coils on the Tesoros?

 

[scdetector]

Are you using DD or concentric coils on the Tesoros?

Concentric coils on the Tesoro’s, AI generated some pretty good answers. Coils were mentioned, I’ll paste part of my research, answered a lot of my questions and by no means saying Tesoro’s are better. I enjoy my Minelab’s and my AT, actually enjoyed all the detectors I’ve owned that kept me in the hobby for 25 plus years but always curious about such a simple paper test

 

[scdetector]

Legacy Tesoro metal detectors (like the Vaquero, Tejon, or Silver µMax) are legendary among seasoned hobbyists for their incredible target separation and unmasking ability. Even though Tesoro closed its doors in 2018, their machines often outperform modern digital detectors in trash-heavy environments due to their raw analog engineering. [1, 2, 3, 4, 5]

The primary reasons Tesoro detectors achieve superior target separation include:



⚡ True Analog Processing (Zero Lag)

Modern digital detectors (like the Vanquish or Equinox) take the analog signal from the coil, convert it to digital data, pass it through complex visual processing software (VDI), and translate it into a screen number and audio tone. This processing takes time, creating microscopic delays. [1, 2, 3]

• The Tesoro Edge: Tesoro machines are pure analog circuits. There is no screen or software delay. The moment the edge of the coil passes over metal, the audio triggers instantly, allowing you to hear a coin tucked tightly against a rusted nail. [1, 2, 3, 4, 5]

🎛️ Minimal Filter Systems

To make visual screens stable, digital metal detectors use aggressive software filtering to smooth out erratic signals from hot ground or nearby iron. If two targets are close together, these filters often merge them into one "jumpy" signal.[1]

• The Tesoro Edge: Tesoro used a very low number of circuit filters. Because the machine doesn't have to cleanly output a number onto a screen, it passes raw, unfiltered audio directly to your headphones. The separation happens entirely in your ears, not through a computer chip. [1, 2]

🎯 Concentric Coil Physics

While most modern detectors ship with Double-D (DD) coils for depth and ground coverage, Tesoro heavily favored concentric search coils. [1, 2, 3, 4, 5]

• The Tesoro Edge: A concentric coil projects a cone-shaped magnetic field that tapers down to a sharp point in the dirt. Because the footprint shrinks at depth, it physically sees fewer targets simultaneously than a wide DD blade, preventing "target masking" in shallow trash fields. [1, 2]

🔊 "Bleed-Through" Audio Nuance

Digital machines cut audio into hard blocks (e.g., an item is either completely iron or completely silver).

• The Tesoro Edge: Tesoro's linear discrimination allows the audio to "bleed." If a good target is right next to iron, you will hear a distinct, blended clipping sound—part iron grunt, part clean snap. This razor-sharp audio behavior allows experienced users to pick out coins that modern machines completely ignore. [1, 2]

 

[Carl-NC]

A unique feature of Tesoro concentric coils is that they use a smaller RX coil diameter than other concentrics. This helps with separation and doesn't really hurt depth any, at least for coin-size targets. Many years ago -- before the current crop of digital MF models -- I tested a bunch of detectors for target separation. The Garrett AT Gold was the best (but it's also a 1st derivative machine so that's largely why) but the Tejon came in second, clearly beating out all the other top-end models. The Cibola and Vaquero are the same design.

Your test paper shows targets that are close enough that you are probably not getting true separation, rather you are getting a composite signal. The composite signal you get will determine whether you hear a beep or not. Many people assume that DD coils have an advantage in separation but not necessarily, especially when it comes to composite signals; the long overlapped region where detection happens is more likely to "see" more than one target. This is where the small RX coil on the Tesoro has an advantage.

AI is correct that digital discrimination creates hard rejection edges so, in my tests, I always turn disc off. I also test with 2-tone where I can get an iron grunt. With Tesoro beep-and-dig models it's tough to tell exactly what is going on because there are no tones and no VDI, so the best thing to try is slowly increasing the disc to see where the composite signal cuts out. AI is incorrect that digital filtering incurs any more delay than analog filtering -- it can, in fact, be made faster and better. AI is also incorrect that a "concentric coil projects a cone-shaped magnetic field that tapers down to a sharp point," it's shaped like a hemisphere. The common lore that a DD projects a "windshield wiper" shaped field is also incorrect except for surface targets, which is how many people do these separation tests.

 

[Tesorodeoro]

AI has never swung a coil.

 

[scdetector]

AI has never swung a coil.

I agree... Personally I don’t like AI but some answers are right and others are wrong same as people’s opinions. Like what’s the best metal detector? The one that finds treasure is a logical answer imo but of course it doesn’t work that way.

 

[snaps]

This has puzzled me for years! I have a piece of paper with a quarter taped on it with multiple trash items I’ve used for years. I have tried a Nokta, Apex, Vanquish 340, 440, 540 along with the Ace series, a F-70, F-22 along with several others and none can pick out this quarter except my Tesoro detectors. I have tried various settings on the other detectors and they are silent except in all metal mode of course. I thought possibly EMF so I ruled that out. It’s like the quarter is masked by the trash. My 540 with the V-8 coil passes over it in coin mode and it May beep depending on the angle but the target ID is everywhere. I have a U-Max, two Cibolas and a Vaquero that will give a solid beep on the quarter, I’ve tried replacing the quarter with a penny with the Tesoro’s and it hits the penny, if I turn the discrimination to full it will not detect the penny. So what’s up with the newer digital detectors?

I bet my Old Compass GSP would pick up that quarter. Never give up your last analog!