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Re: The Discriminating (to iron) Pulse Induction. - Fantasy? .....Facts.!
Posted by: Dave J.
Date: December 29, 2015 08:13PM
MP, if ya wanna know how the White's multifreakers work, just give Kenny White a call and ask him. If ya wanna know how Minelabs work, just call Mr. Codan and ask him. And if ya wanna write a book on how metal detectors really work...... well, before embarking on that quest, first ya might wanna see how many people post here saying they're looking forward to reading it.

Re: The Discriminating (to iron) Pulse Induction. - Fantasy? .....Facts.!
Posted by: metalpopper
Date: December 29, 2015 09:36PM
Good evening Dave..........Glad to see you are alive and kicking, despite what mother-nature is throwing down.

There's been enough rain to float an ark; so the outcome for metal detectorists, is potentially intriguing.

I have a test-bed in my garden, and known targets that have been 'stable' for over 45 years, are now taking on different characteristics.

I suspect the water has penetrated sufficiently such, that dormant, deep, dry, ferrous items local to my 'non-ferrous' .ones, are now 'oxygenated.

It will be interesting to hear from others, whose own set-up shows any such changes.

............................

So you think I should write a book ?..!!!!!!!

Would you give me permission to use your forum contributions to illustrate some of the technicalities we've endeavoured to discuss on the Technology forum ?

Knowledge is initially born as a statement of someone's ideas. Whether they are accepted by the majority, is dependant on two things; the originator's communication skills, and the ability of the recipients to analyse what's offered.

Offering an opinion, right or wrong, is in itself not the most important aspect of such; but rather the stimulus it provokes by attracting constructive debate on WHY each participant thinks differently.

So in that spirit Dave, can you add your technical thoughts as well as your entertaining bluster.

I'm sure, all input will be eagerly followed, especially when donated by a man of the trade.

Matt.



Edited 1 time(s). Last edit at 12/29/2015 09:39PM by metalpopper.

Re: The Discriminating (to iron) Pulse Induction. - Fantasy? .....Facts.!
Posted by: Dave J.
Date: December 30, 2015 04:27AM
I think you should write a book.

Re: The Discriminating (to iron) Pulse Induction. - Fantasy? .....Facts.!
Posted by: Hastings
Date: May 13, 2016 11:49AM
Does anybody know about any new developments in this area?

Re: The Discriminating (to iron) Pulse Induction. - Fantasy? .....Facts.!
Posted by: kt315
Date: May 20, 2016 11:30AM
Dave Jonson is active in geotech and you can ask him directly http://www.geotech1.com/forums/member.php?6331-Dave-J
Biography:chief engineer FTP-Fisher..... Please don't PM me asking for information about metal detectors, that's what the forum is for. Beeping on metal is my day job, and anything beyond that is entertainment.Location:El Paso TX, Citizen of the Universe.Interests:Surviving Lou Gehrig's Disease & sharing howOccupation:Feeding hungry people. Worst sin known to man.

Re: The Discriminating (to iron) Pulse Induction. - Fantasy? .....Facts.!
Posted by: metalpopper
Date: February 28, 2017 05:14PM
Quote
trojdor
Matt,
I think it may boil down to an attempt to arbitrarily redefine how some already arbitrary terms are generally/historically accepted.

We've seen this throughout the history of the metal detector. ...

.(.Did you ever read about 'Flat-earth believers, trojdor?)
It appears that we have a few in this thread, reincarnated as metal detectorists !.....matt

The original term 'T/R' is used to designate an early transmit/receive unit that doesn't ground balance.
It's already inaccurate, in that the correct term is 'induction balance'...but we'll gloss over that, and simply state that because the majority of us accept that T/R means an older non-GB detector, we all understand it.

The later term 'VLF', generally used to distinguish a ground balancing unit, is by it's own wording totally arbitrary. 'Very Low Frequency'...totally nebulous term...has nothing to do with GB...but we all accept what it means.
(Note that the VLF still utilizes the same type of inductance balance to get a signal as the TR...only the processing is different...but that term was already used for the IB/TR, so we needed something else.)

Now you would like to take the term 'PI' and redefine it's generally accepted usage. You might even be correct in that your terminology is grammatically more accurate...but it doesn't matter.
Like the terms T/R and VLF, the generally accepted definition of PI has been in use for some time, and you can't undo history. It's already in use as a generally accepted term throughout the industry.

It's kind of like the joke; "They had to call it PMS because Mad Cow Disease was already taken."


Something akin to 'literal Luddite's' disease?..........Matt


Re: The Discriminating (to iron) Pulse Induction. - Fantasy? .....Facts.!
Posted by: metalpopper
Date: March 09, 2017 07:38PM



Re: The Discriminating Minelab's modern PI's.....Facts.! The silence of the knockers speaks volumes.N/T
Posted by: metalpopper
Date: July 18, 2017 07:45AM

(This message does not contain any text.)


Re: The Discriminating Minelab's modern PI's.....Facts.! The silence of the knockers speaks volumes.
Posted by: metalpopper
Date: September 10, 2017 08:53AM
https://www.google.com/patents/US9239400
For Dave.....From Minelab.


Metal detectors can be divided into two main types, depending upon the nature of their transmit field; CW (Continuous Wave) and PI (Pulse Induction) detectors. Some CW detectors transmit magnetic fields that have substantially only one sinusoidal frequency. Others can transmit a transmit magnetic field that is a combination of some small, finite, number of frequencies or, through application of a rectangular transmit signal to a broadband transmit circuit, a large number of frequencies.
PI detectors usually include switching electronics in the transmit electronics, producing a large number of frequencies in the transmit field.

Read it and retract ......matt

Re: The Discriminating Minelab's modern PI's.....Facts.! The silence of the knockers speaks volumes.
Posted by: Carl-NC
Date: September 13, 2017 07:53AM



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