Do Digital Detectors Lose Depth Over Time?

[Digalicious]

Hi All.

If someone was to take for example, a new Nox and compare it to the depth of a Nox that has years of use and thousands of hours on it, would the depth be the same?

I mean, I can see how analog components will eventually lose tolerances, and cause some sort of performance problems, but does something similar also happen with digital components?

[phrunt]

I think people get this impression as they buy a new computer, use it a few years and then it's really slow and clunky and they think age caused it when really, it's just bogged down with crap from the years of use and loads of updates, wipe it and fresh install Windows and it's like new again.

Run benchmarks on it when it's new, and after being wiped and reinstalled years later and the results will be the exact same, many years apart as long as its not developed any hardware issues, most likely the hard drive being the mechanical component being susceptible to wear causing it to slow down or have performance and reliability problems, fortunately our Nox's don't have hard drives for their software 🙂

I can't imagine a 5-year-old Nox performing any different than a brand new one unless it's developed a fault or the battery is failing.

[Digalicious]

12 minutes ago, phrunt said:

I can't imagine a 5-year-old Nox performing any different than a brand new one unless it's developed a fault or the battery is failing.

I can't imagine it either, unless the digital detectors still have some analog components that lose tolerance over time. I thought I'd ask, in case I was missing something .

On a side note:

Ditto on the mechanical drive. I've replaced hundreds of mechanical drives with SSDs. The speed difference is nothing short of phenomenal, and that's true even with cloning, let alone a clean install of the OS.

[RickUK]

Some of my detectors ie like my DFX which is 20 years old and my T2 which is 18 years old still perform exactly the same as when they came out the factory,my DFX certainly has 1000s of hours of use over the last 20 years but just these 2 old detector have found me more gold/silver hammered and milled coins than all my other put together.

So my answer would be no unless they have been mistreated or modified internally that is.

[Geotech]

13 hours ago, Digalicious said:

I mean, I can see how analog components will eventually lose tolerances, and cause some sort of performance problems, but does something similar also happen with digital components?

No, digital components don't change with age. The newer detectors still have 3 elements that can change, though: the coil, the preamp, and the ADC. The ADC and the opamp used in the preamp are pretty stable. The coil can shift over time, but that will mostly change the null and affects the  point where it overloads, but depth should not vary. The preamp has resistors and capacitors, and that's mostly where depth variation can occur. Ironically, many newer designs place the preamp inside the coil so replacing the coil might be the solution if depth degrades.

[phrunt]

50 minutes ago, Geotech said:

No, digital components don't change with age. 

Thank you, Carl, you're a real asset and I appreciate every post you take the time to do, always informative.  

[Digalicious]

Thanks Carl, for clearly explaining the analog components of the mostly digital circuitry.

If you would be so kind, can you please elaborate on "Many newer designs place the preamp inside the coil"? More specifically, what is the necessity, or preference reason for placing the preamp in the coil? Also, of the SMF detectors from the original Nox and forward, do you know which of those has the preamp in the coil?

[Geotech]

Placing the preamp in the coil improves noise immunity because the RX signal from the coil to the control box is now driven by a low impedance and has also been gained up. Minelab started this with the original X-Terras (30/50/70) and I assume all their detectors are now designed this way. I'm not sure if Garrett or Nokta do this, and XP obviously does.

[Digalicious]

Nice. Gain increase by placing the preamp before the coil cable. That makes sense! Thanks again Carl 🙂

[Steve Herschbach]

With Minelab it stated as Carl notes with the old X-Terra series and V-FLEX. The whole thing about using chips to keep others from building coils is more a side effect than the original intent, which was to improve performance. The signal is boosted at the source before it can weaken or before extraneous noise can enter via travel up the cable. From the Minelab website (emphasis added):

VFLEX uses state of the art digital electronics to enhance standard single frequency detection technology. This has the advantage of providing dependable performance and improved immunity to outside interference. VFLEX technology also has an added advantage that changing the detector’s coil also automatically changes the detector’s operating frequency. This means that an X-TERRA detector can operate at different frequencies allowing the detector to be easily modified to suit different detecting conditions.

VFLEX provides increased detecting performance with perfect sine wave transmission, an in-coil signal booster and coil selectable transmit frequencies.

VFLEX transforms conventional single frequency metal detection technology by including two microcontrollers (miniature computers), one inside the control box and one inside the coil. Every time the detector starts up, the microcontrollers establish communication via a digital data link. The coil microcontroller communicates the coil’s configuration, size and exact frequency, so the control box can generate a perfectly matched transmit signal. This significantly reduces distortion and increases Target ID accuracy.

VFLEX technology generates and transmits a perfect high quality sine wave, using the same technology that is found in high quality digital audio players, and is produced without distortion. The removal of distortion maximizes power transmitted from the coil, therefore increasing detection depth and sensitivity. This also results in enhanced Target ID accuracy and greater immunity to both ground and environmental noise.

VLEX employs an In-Coil Signal Booster. Weak target signals are amplified inside the coil, before the receive signal is sent up the coil cable where interference and signal loss can occur. This technique improves immunity to electrical noise by reducing false signals and increasing target signal strength, therefore improving detection depth and sensitivity.