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Steve Herschbach

Selectable Frequency And Multiple Frequency

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20 hours ago, Steve Herschbach said:

It also hurt that for a long time the Vision, V3, V3i, and I assume VX3 all suffered from serious EMI issues in some places. I found the machine unusable in many places in Anchorage, Alaska, particularly around buried power lines. So much so I recommended a special anti-interference coil be wound for the machine. White's really should have listened to me but did not, and that turned a lot of people off the V3i. They did apparently finally get a handle on it however as my last one seemed to finally work well around EMI sources.

Nothing was ever changed for EMI issues.

20 hours ago, Steve Herschbach said:

The V3i was planned to have a dongle and a PC computer interface. I think things would have been different if that promise had been truly delivered on. The perfect PC interface for the V3i would allow the user to modify all the settings on their PC from a large master menu. It would include an emulator mode to test various settings and show how the screen would look in use. Programs could be stored and traded online with other users. I am not saying and frankly doubt Whites would have done this dreamed of interface right, but the possibility was there. It would have created a cottage industry of V3i programmers that would have provided the impetus to really develop the V3i to its full potential. Unfortunately Minelab threatened to sue over the same thing they are currently suing XP over as regards detector data transfer patents, and Whites folded without a fight. I think they may have won but lacked the vision to see the true potential and decided a fight was not worth the cost. The repercussions of that are still with us.

The PC interface was done and working, really nicely. I pushed hard to challenge the ML patent but was alone in that effort. I expect XP will win.

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XP will win but probably don't win with conception of software and Depar. Some Russian hackers made XP standalone software for Deus. Other work to hack Depar units and made cheap Deuses... or put software into cell phone... 

 

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23 hours ago, MikePfeiffer said:

Carl, I was wondering why the manufactures have not incorporated a sweep frequency from, let's say  0 to 100 kHz.

This idea has been batted around for years but, to my knowledge, has ever been implemented. Several reasons why come to mind:

1. Target responses don't vary a whole lot until you get beyond a 2:1 frequency ratio. That is, the difference between 10k and 12k isn't enough to make both of those frequencies worthwhile. So we could sweep the following: 1k, 2k, 5k, 10k, 20k, 50k, & 100kHz. 7 frequencies would give you all the information you need, maybe even as little as 4.

2. Most detectors use zero-IF demodulators and for good SNR require multiple cycles of the frequency. The more frequencies you have, the less time the demods have to accumulate data. Beyond 3 or 4 frequencies you'll see this as a lag in responsivity. On the upside, it would be a good method for pinpointing where lag is not important, and you could even do full non-motion (static) disc. In fact, White's has a patent on a "zero motion 3F disc method" that was supposed to end up in the V3 but did not. Ideally, you would want to use direct sampling in a sweep-frequency detector, but this requires a really fast high-precision ADC. Direct sampling detectors (X-Terra, Go-Find, Prizm 6T, Deus) currently max out at less than 20kHz.

3. Sweeping the TX across a wide range of frequencies is easy, a DDS can do it. But as the frequency increases the coil current decreases, so a 100kHz TX signal would be very weak. You can see this in Minelab BBS/FBS detectors, where the 25kHz TX signal has 1/8th the strength of the 3.125kHz signal; they go deep on silver, but don't do well on small gold. Solving this means increasing the TX voltage with frequency which sounds easy but it's not.  Designing a coil to work well enough over a 100:1 frequency range that you can easily swap coils without having to recalibrate the detector is also a huge challenge.

4. Until about 10 years ago the processing horsepower just wasn't there. Now it is, but it takes a while for detector companies to catch up to what the rest of the mass electronics market is widely doing.

So a sweep-frequency detector is doable, but I'm not sure it would offer the benefits people imagine it would. Probably a wide-band 3F detector would offer 99% of the target ID benefits while being overall more usable and deeper.

 

 

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52 minutes ago, Shelton said:

XP will win but probably don't win with conception of software and Depar. Some Russian hackers made XP standalone software for Deus. Other work to hack Depar units and made cheap Deuses... or put software into cell phone...

Deus uses a PIC24F processor, which is simple to hack and almost impossible to code-protect. By taking the Deus to the African market XP was begging to be hacked.

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Or Russian.... and Ukrainian. Some ours hackers work on it too ;)

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2 hours ago, Geotech said:

Nothing was ever changed for EMI issues.

In that case I never should have sold my last V3i - I somehow got a "good one". After all this V3i talk I would like to get another one but that would worry me. I never would have sold my last one were it not for the 22.5 kHz not playing well with my Bigfoot coil. The VDI numbers triple in 22.5 with the Bigfoot, causing coins to wrap into ferrous readings, and giving weird responses in three frequency mode. It ran fine in 2.5 kHz or 7.5 kHz. However, at least one guy (Tom Slick?) has been using the VDI skewing to advantage. The jewelry / aluminum range spreads out tremendously, and supposedly the aluminum skews higher faster than the rings.

Sure would like to have seen that software interface come to fruition! The original V3 could transfer a program from one V3 to another wirelessly. This was to be the basis of the V3 to wireless dongle scheme. The wireless transfer option was dropped or hidden in the V3i upgrade. From the V3 Owners Guide page 31:

Share - Allows sharing of program settings by Transmitting (sending a program) to another Spectra or receiving (getting a program) from another Spectra.

Transmit - Send one or more of your programs to another Spectra.

  • ENTER, then select where to get the programs to send.
  • Menu (Menu & Live Control List) or Library. Menu/Tab to SEND, ENTER.
  • Wait until transmitting completes one or two cycles through 100%.
  • Press ENTER to end transmission. Menu/Tab to EXIT, press ENTER.
  • Note: The other Spectra has to be set to RECEIVE, on the same channel as you are sending.
  • Saved Programs; Select a program from your Menu or Live Control listing.
  • Library, select All Programs or just an individual Program to send from your Library.
  • Channel; select a channel free of interference (majority green in bar) and select same channel within other Spectra (Receive Unit).
  • Speed; Select the speed the data is sent, mid range to slower speeds generally more reliable

Receive - a program from another Spectra that is Transmitting.

  • ENTER, then select how to receive the program.
  • ASK, Asks you (after receiving) how and where to save each program.
  • STOP – Stop receiving Programs.
  • Ignore – Don’t SAVE this Program (skip).
  • Create Library – Add Program to existing Library.
  • Create Program – Add Program to regular MENU and Live Controls (if there is room) , not Library.
  • Update Library – Replace existing library programs with new programs being received.
  • Create Library – Add receiving Programs to existing Library.
  • Create Program – Add receiving Programs only to Menu & Live Controls (if there is room).
  • Update Saved – Replace Programs of same name with new received Programs.
  • Update Current – Update only Programs of same name on Menu and Live Control listings.
  • Don’t Rename – Keep same name as sent. A. B. C. added to front of new programs using an existing name.

And another tidbit from Carl's post at http://forums.whiteselectronics.com/showthread.php?44191-V3i-Information

"Wireless Data Transfer & Dongle

Much ado has been made over this issue. When we released V3 I had intended to produce a dongle that would allow transfer of programs to/from a PC, and said so when someone mentioned this idea. In fact, I personally took this on, got the initial hardware working, and started on the software. Other priorities forced me to hand it over to another engineer, who got it mostly working.

However, we've run into two issues with this. One is that the transfer is slow and unreliable. Unless conditions are near-ideal, packets are dropped and, because the design of the RF module makes handshaking difficult, the whole transfer has to start completely over. Second, the release of V3i introduces a different program data structure that creates compatibility issues between machines. Dealing with this requires a lot more programming effort, both in V3/V3i firmware and in the PC software.
"

And finally, from the V3 Engineering Guide:

"Why not Bluetooth ...

Wireless headsets for metal detectors are often a disappointment. The audio response from the detector often does not reach the headset while the loop is over the target. Most metal detector user’s sweep speed is at least 96” per second. Most wireless transmits and receivers (including Bluetooth) use a protocol that is much too slow resulting in target audio that lags the actual target.

White’s engineers solved the problem with a dedicated microprocessor, custom TX/RX protocol, and the selection of a pair of super fast Cypress CYWM TX/RX modules. The results are crystal clear audio, and “real-time” target detection housed in an American made and engineered housing specifically designed for
use with Spectra V3.

The CYWM modules also serve to transmit and receive program data between two or more Spectra V3 detectors. This transfer feature allows for development of custom programs to be shared via a wireless pathway."

Instead of wireless transfer, it is too bad the V3 had no USB port for a hardwired hookup to a PC.

 

Carl, you guys were so ahead of your time in so many ways. The Vision/V3/V3i is still a wonder to behold. And many companies just now seem to be getting a handle on the Bluetooth lag issue - White's did it ages ago. I wish they had retrofitted the wireless capability to other models and/or produced a wireless receiver module so headphones other than the one Spectra model could have been used.

From a post by Alan Holcombe (past White's CEO) at http://www.findmall.com/read.php?66,933247

"A word about Vision technology: White's does not have an agreement covering Vision technology with any person, company, organization or country. The Vision concept came directly from Ken White. All of the research, engineering, software, hardware, development and intellectual property are owned in total by White's Electronics Incorporated. Vision is the work-product of Design Engineers, John Plautz, Anne Kelly and Jeff Kelly, in consultation with John Earle, Allen Hibbner, Brian Huppy, Bob Canady and others, all directed by Engineering Manager, Carl Moreland."
 

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I have a V3i and it has been a good one... 

I would love to see White's expand on that platform.

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I'm not feeling near as pissy as I was when I learned that my wireless pinpointer patent was dropped and XP would own that technology, so I won't comment on all the behind-the-scenes stuff other than to say, official statements rarely reflected reality. One bit of truth was that the Cypress module has a low transfer rate (62kbits/sec as I recall) which is good enough for audio packets, but transferring programs turned out to be slow and prone to drops. New modules are 15-30x faster and can easily do the job. And it's only with Bluetooth 4 that BT audio has gotten fast enough to be usable for detectors, but still tends to be more power-hungry than using a proprietary protocol.

 

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15 minutes ago, johnedoe said:

I have a V3i and it has been a good one... 

I would love to see White's expand on that platform.

Probably never.

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Carl, thank you for replying. I read your book and it was very educational. I had planed on designing my own detector as I did not see much progress from manufactures. However, after reading your book, I quickly learned it would take me years to get up to speed. Thanks again!

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