Silver Detector

[Steve Herschbach]

Hi,

It is obvious that lots of people using metal detectors like to look for silver coins. Like many, there are times I wish I could just set my discrimination just above copper penny to get silver dimes, etc.

My White's DFX if set for 3 kHz only and normalization turned off does show a small VDI difference between coppers and even clad dimes and silver dimes in air tests. It seems tantalizingly close to being able to do the trick.

So the question for you techinical experts is this. Can a detector be designed for the sole task of trying to make the split in discrimination at this point as wide as possible? Perhaps a lower frequency of 1-2 kHz and all the discrimination resolution focused on the small range from copper penny to silver dime?

I realize ground effects and corrosion throw a wild card in but frankly I'm at work and a bit bored so thought I'd see what you guys think.

Have a great Thanksgiving!!

Steve Herschbach

[Cody]

Re: Silver Detector

The detector would be expensive and as in the case of VDI numbers would need to be more defined such as 94.0005 instead of 94.2. You can get that third digit with the DFX if you set the VDI sensitive high enough but you still don't have enough definition as you indicate.

Cost aside, how do we deal with the problem of a core that constantly changes, the soil matrix, and is never the same from one instant in time to another if the coil is in motion? I don't believe the parameters, metal alloy, temperature, soil matrix, surface area, thickness, and the electrical properties, inductance, conductance, conductivity, etc, and the magnetic properties in conjunction with the soil matrix allows all copper to be separated from silver.

I can set the Explorer11 or DFX to find just about nothing but silver, clad silver and very little copper coins. The soil matrix is the primary reason why I don't think it can be 100%.

Cody

[Steve Herschbach]

Re: Silver Detector

Hi Cody,

I sort of agree, but when I bought my first detector it was impossible (or too expensive) to discriminate metals at all with a metal detector.

As you note we are very close at the moment, and although I'd not expect 100% it surely seems a bit more could be done if that were the primary focus of the device.

As far as price goes Minelab has proven people will spend $3000 for a single detector. Many detectorists have multiple machines that add up to far more than that. Build a better "silver detector" and you might be surprised what someone like me (or you Cody!) would spend on one.

Steve Herschbach

[Cody]

Re: Silver Detector

Yes, I do understand and I would most likely need to have one. Frankly I don't think there is a depth problem but a discrimination at depth that can tell aluminum from other metals and group metals into gold, silver, and copper then junk. They actually do a pretty good job with iron but aluminum give them fits. I am not interested in a detector that tells me this may be a tab but one that tells me this IS a RING. We do seem to get closer each year so will see what comes of it.

Hope all is going well for you and good to see your post.

Cody

[Carl-NC]

Re: Silver Detector

Hi Steve,

IMO, clad ain't worth digging, unless there's a whole lot of it, and it's virtually on top of the ground. I agree, a silver-only detector would be nice to have in some situations. The problem is, clad conductivity is incredibly close to that of silver.

As I understand it, lower frequencies tend to expand the high-conductivity phase response, and compress the low-conductivity phase response, while higher frequencies do the opposite. I'm not sure how much shift there is in phase resolution, but it might be possible to use something like 1kHz to get better silver separation.

- Carl

[Sean Goddard]

Re: Silver Detector

Any of you tried a Compass machine????

In the UK they are legendary for finding thin section silver Tesoro are right up there with them too, and BOTH are US made so you will be supporting US industry, something which it need these days!

[Cody]

Re: Silver Detector

I used one of the first on the market just after the engineers that founded Compass left Whites. It was the best TR machine I had used up to that point and was in the early seventies.

I don't know what happened to them over the years as they had very good products for many years and I used them and Whites for years. I recall when Tesoro came on the market so it was Compass, Whites, and Tesoro. Garrett was really stuck in trying to make the BFO fly but it was blown away by the TRs so he ended up with a TR that was always behind the others in performance.

George Payne invented the VLF and Bounty Hunter turned them into a motion discriminator and then it all changed. I have pretty much gone to multiple frequency machines after Minelab invented that process as I believe there are some real advantages in that technology.

I rotate around from time to time but like the operation of the DFX, Explorer and Sovereign Elite. I am always looking for the next serious technology but don't care much for changing the code of the microprocessor or a different size resistor as being the latest engineering break through. I am worn out with that as the new super detector for depth and discrimination and don't really have any interest in those new hyped machines. It turns out to be like a new car each year with nothing really new at all other then the paint and year of production. Over forty years of the newest deepest detecting machine or coil to do the job has burned me out. It all that was true then by now we would be detecting dimes at a minimum of 10 feet through solid quartz.

I hated to get to this point but I want to see it and test it and don't expect anything when I do other than what has been around for several years.

Cody