Metal Detector Engineer's Who Led The Way Dave Johnson & Bruce Candy

[RONS DETECTORS MINELAB]

I was looking though some blogs on electrical engineer Dave Johnson and Bruce Candy and was amazed at how much of our best detector technologies have come from these two inventors. I'm sure there is more people to give credit too also but these two have really left a milestone. 

Here's below is a Q & A from Dave Johnson

Question 5:

DS: Would you mind giving us a list of detectors you’ve had a hand in developing?

Dave: “Old Fisher: 1260, 1220, 1210, 1225, 1235, 1265, 1266, 1280, Impulse, CZ6, CZ5, CZ20, Gold Bug, Gold Bug II, TW6/Gemini, FX-3, and several industrial products.

Tesoro: Diablo MicroMax, Lobo Supertraq.

White’s: DFX, Beachhunter ID, GMT, MXT

Troy: Shadow X5

Bounty Hunter & related products: nearly everything we manufacture. Many of these products are adapted from the original Teknetics which was designed by George Payne. The Teknetics T2 however was an entirely new design.

New Fisher: F75, F4, and everything else since then.

On most of the above I was the lead engineer. On the White’s DFX and Beachhunter ID I developed the multiple frequency circuitry, and other engineers designed products around that circuitry. In addition to the above there are many products on the market which are adaptations by other engineers of products I designed.”

John: “Bounty Hunter : I have had a hand in most of our current line up from the bottom to the top, from Guardian to the Time Ranger.

Teknetics : T2 I was main programmer

The Fisher’s : The F4 and F75”

Question 6:

DS: Are we about “maxed out” as far as how deep VLF units will go? In your opinion, what’s the biggest obstacle for current technology in achieving increased useable detection depth?

Dave: “Getting extra depth out of a VLF, multifrequency, or PI machine is very difficult, because these machines follow an inverse 6th power law relationship between signal voltage and depth. If everything else is maintained equal, doubling the depth requires 64 times as much signal. If this is done by increasing transmitter power, doubling depth requires 4,096 times as much battery drain. That’s the basic reason why depth increases come so slowly in this industry.

The biggest impediment to getting usable depth in the ground, is interference from magnetic and electrically conductive minerals in the ground, which can produce signals hundreds of times as strong as that of the metal target you’re trying to detect and hopefully identify. There are several approaches to extracting the metal signal from the ground mineral signal, but they all have their limitations. That’s why you see several different technologies coexisting in the market.”

John: “Dave points out biggest obstacle which is seeing target through the Ground and Air interference.”

Question 7:

DS: If you had to pick one existing feature on the F-75 that you’re the proudest of, what would it be?

Dave: “If we can include the T2, it’s a tossup between the ergonomics and the target separation. Both aspects of the design were huge leaps forward.

If you mean just the F75: the fact that on the F75 we pushed sensitivity even further than on the T2. As I said a few questions back, more sensitivity is very difficult to get in this industry.”

John: “One of things I like best about the F75 is it has the ability to give I.D. values while in static mode.”

Question 8:

DS: Are TID pulse units the hobby future? Or, what do you think will be the next great advancement in metal detector technology?

Dave: “About 1985 I built a real sweetheart of a discriminating PI unit, not very hot in air test, but it was simple, lightweight, powered by one 9 volt “transistor battery”, ran quiet in bad ground, had no bad habits, and you didn’t have to dig any trash. It morphed into a fully static TID machine which Fisher came close to releasing about 1989, but its reliance on fully static operation which was supposed to be an advantage, was in fact a fatal flaw for a TID machine. Stripped back down, it became the Impulse which was strictly all-metals.

Industry insiders know about a PI TID machine which a fairly sharp freelancer has had under development for about 5 years and which is said to be nearing production. Whether or not that one makes it, I expect there will eventually be others.

The next great advancement in metal detector technology will be….. ahem… we’ll all know when whatever it is actually hits the market and customers say it’s a great advancement. I hope that when that event happens, it’s got our trademark on it. If it’s got someone else’s trademark, I guess we’ll just have to play leapfrog.”

 

Bruce Candy had the most PI/ZED Technology advancements and is still applying for patents in 2024.

 

 

[araratgold]

Yes, there is no doubt Dr Bruce Halcro Candy is an absolute genius. 👏

Don't know the other guy, but obviously a very smart man as well.

Rick

[goldenoldie]

Did BC have anything to do with the Gpx6000 as it not mentioned on the chart?

[phrunt]

1 hour ago, goldenoldie said:

Did BC have anything to do with the Gpx6000 as it not mentioned on the chart?

Yep, the only recent patent on it was under his name.

US11454736B2 - Metal detector - Google Patents

But even the earlier patents used for the 6000 from 2013 were also under his name.

This 2012 fast time constraint target detection patent was for the SDC, but it's also used on the GPX 6000 and was under Bruce Candy also.

We can go right back to 2006 patents like this one used on the GPX 6000 also by Bruce.

This 2016 patent used on the 6000 is also under Bruce.

Basically, every single patent for technology in the 6000 is under the name Bruce Candy so I would say he had a lot to do with it, all older patents used also on other detectors except the first one which was is the only one not used in other detectors, so far, it's exclusive to the 6000.

[RONS DETECTORS MINELAB]

1 hour ago, phrunt said:

Yep, the only recent patent on it was under his name.

 

These guys were the Einstein’s of the metal detector industry, I guess once they retire replacing them would be quite challenging for these companies.

I am glad Alex is starting to take off very well with the start of the Algoforce company. Seems like he’s has some of the best new inventions and patents for new technology out there recently. 

[GB_Amateur]

16 hours ago, RONS DETECTORS MINELAB said:

Here's below is a Q & A from Dave Johnson

I think the 'John' who was part of this interview is John Gardiner, another First Texas Engineer.  Unfortunately Steve H. mentioned in another thread that First Texas's new website no longer includes several informative articles, etc.  I'm pretty sure this was from one of those although you didn't indicate where you found it.

[RONS DETECTORS MINELAB]

Teknetics home page and tek files

1 hour ago, GB_Amateur said:

I'm pretty sure this was from one of those although you didn't indicate where you found it.

 

[Steve Herschbach]

George Payne

[GB_Amateur]

2 hours ago, RONS DETECTORS MINELAB said:

Teknetics home page and tek files

https://www.tekneticsdirect.com/blog/the-tek-files

thanks.  These are some of the files that used to be on the (old) FisherLabs webpage, but not all of them.  Hopefully the others will re-appear....

[RONS DETECTORS MINELAB]

On 3/31/2024 at 5:38 PM, RONS DETECTORS MINELAB said:

Dave Johnson

On the White’s DFX and Beachhunter ID I developed the multiple frequency circuitry, and other engineers designed products around that circuitry

Looks like Dave and Minelab were working on the same type technology developments about the same timeframes.

 

On 3/31/2024 at 5:38 PM, RONS DETECTORS MINELAB said:

Dave: “About 1985 I built a real sweetheart of a discriminating PI unit, not very hot in air test, but it was simple, lightweight, powered by one 9 volt “transistor battery”, ran quiet in bad ground, had no bad habits, and you didn’t have to dig any trash. It morphed into a fully static TID machine which Fisher came close to releasing about 1989, but its reliance on fully static operation which was supposed to be an advantage, was in fact a fatal flaw for a TID machine. Stripped back down, it became the Impulse which was strictly all-metals.

I like that Dave says this special PI he made with the Static TID allowed him not to dig any trash. 

 

On 3/31/2024 at 5:38 PM, RONS DETECTORS MINELAB said:

Industry insiders know about a PI TID machine which a fairly sharp freelancer has had under development for about 5 years and which is said to be nearing production. Whether or not that one makes it, I expect there will eventually be others.

I guess this has finally happened after all these years but not sure if he’s referring to the pinpointing static TID option.