Pulse Induction Training - Wet-Salt

Ed…… the ratio of: Dollars Invested...…. vs …….. Time expenditure/Tuition-gain .,.,.,.,.,.,., would conclude: Sub-par R.O.I. >>> Sooooo….. not worth it!

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I have finally come to the conclusion: Beach Hunting is NOT a niche market. Confirmed. First-hand.

Good, cause after looking at a 920 stealth with carbon, my heart skipped a beat.

What I will do is scour this forum and the internet for golden nuggets on PI.

While we wait for the fisher machine, I might as well become educated.

I just love Tom's Training episodes. Often more questions arise for me, which I enjoy.
Just cut out some parts as I otherwise lose overview with a full quote.
...
> 3. CONDUCTIVITY. The higher the Kt rating of the g
> old...…. the more diamagnetic it is; yet/however..
> .…. the more 'conductive' it becomes. (((Robbing P
> eter …… to pay Paul))). The higher the Kt rating/p
> urity of the gold item...…. the lessor the magneti
> c memory; yet/however, , , , , , the more 'conduct
> ive' it becomes...…. tieing in to: 1) size, 2) Xmi
> tter interference, 3) resonance.
...
What do you mean by "resonance" in conjunction with a PI?

I have never heard of that before.
...
> One of the neatest tests you can do is: Go buy a l
> ight-weight/hollow 10Kt White Gold Crucifix/Cross
...
I know a little about PM alloys and am wondering of what type your "standard" 10K test crucifix would be?

Added metals for white gold can be singular or multiple, like Silver, Copper, Nickel, Zinc or Palladium.
Perhaps it makes a big difference, maybe not. I assume this has yet to be determined.

Along this line:
I have a nice graph somewhere in my computer depicting the el. resistivity of platinum in conjunction with common alloy additions up to 20 percent.
There is approximately a difference of one half magnitude to be seen at its highest. Especially with Cu and Ag as additions.

Your post also caused something to spring up in my mind which led to a quick back-of-a-napkin calculation.
Precious metal content is commonly measured in percentile by weight.
Might it not be more interesting from an inquisitive detectorists' point of view to take on the perspective of the volume percentile?
For what it is worth here a quick approx. writeup with copper as assumed alloyed metal:

Fineness Au in K weight % Au volume % Au
0.375 9 37.5 22
0.750 18 75.0 57
0.917 22 92.0 83

The formatting gets mixed up when posting, so I've made some columns bold to distinguish them.

Also:
The crystalline structure of jewellery alloys can vary vastly.
You can have two optically identical rings of the same alloy which are manufactured differently.
They will even sound different to each other when, say, dropped on a table.

Add some salt, water, surf and some years ... metal leaching ...
... off we go down the rabbit hole, heck this is fun ... who knows where this will lead ...

I've rambled on long enough ... over and out for now.

Scoopy_Doo…… I'm a little short on time; yet, MUST start to answer your questions.

3. CONDUCTIVITY 3) resonance. = For instance: A identical size/shape 14Kt wedding band....vs....a 24Kt wedding band. The resonant frequency of the 14Kt vs 24Kt rings are dramatically different. In my collection.... I have a Size 10, 14Kt wedding band that is nearly identical to my personal Size 10, 24Kt wedding band. The resonant freq's of the two devices are dramatically different. The 14Kt wedding band ID's in the very high end of the 'foil' range...…. and my personal (24Kt) wedding band ID's WELL ABOVE the Zinc penny range..... deep into the 'high-coins' range. It is in this delta/differential 'signature-to-hull-emitter correlation' resonance that presents the two very distinct (differing) resonant freq's of each individual gold ring. Ones resonant freq is that of a tongue-of-a-soda-tab...… and the other looks like a silver dime.
(To possibly convolute even more): The principle definition/operation of a Pulse Induction detector is: Transmitter 'ON'...…. then...… Transmitter 'OFF'. When the Transmitter is 'ON'.... it is transmitting on a certain/specific frequency. The frequency may be more resonant to silver.... or may be more resonant to foil.

To answer another of your questions: One of My "Standardized Test-Standard" Crucifix is 10Kt white gold. It's solo alloy is: Nickel. This crucifix is a terrible conductor..... and can hardly be detected.

Outta time..... again!!!

You have a difficult target there no doubt. 10k.....white gold....then throw in cross. Small crosses alone can sound like JUNK just the way they are made

Talking about resonant frequencies. I suppose most PI detectors are designed to detect small gold nuggets. If I were to design one to best detect silver, What would be the best frequency (resonant) pulse width, pulse voltage and delay? not concerned about battery size or life, internal noise, normal design factors ect. If there are other factors that would to help detect silver to be considered add those also. Thanks



Edited 1 time(s). Last edit at 04/13/2019 04:51PM by BamaJoe.

Waiting...anyone...

I thought this was an interesting thread. There really is a lot of good PI info when Mr Bill and Eric was posting...... all kinds of SMART people were responding. Anyone planning to use a machine like the Aquastar needs to take the time to go thru similar threads. The first one is a very good read about depth... not the nickel depth.

[www.findmall.com]

[www.findmall.com]

[www.findmall.com]



Edited 3 time(s). Last edit at 04/16/2019 06:53PM by dewcon4414.

Thank DEW, I read all three links to findmall. I will go over to findmall and read behind EF some more.Tthanks again.

I know very little short of having used a couple PI. So I sure welcome information. I’ve been around long enough to some....but I like it when Tom starts teaching

dew, I'm in the process of building Carl's Hammerhead PI detector with thoughts of modifying it with some thoughts that I have. If the mods work then I'll try modifying my TDI. I've been over at findmall reading up on the Mirage version of the hammerhead. Thanks for your help.

BamaJoe Wrote:
-------------------------------------------------------
> dew, I'm in the process of building Carl's Hammerh
> ead PI detector with thoughts of modifying it with
> some thoughts that I have. If the mods work then I
> 'll try modifying my TDI. I've been over at findma
> ll reading up on the Mirage version of the hammerh
> ead. Thanks for your help.

I also use a Mirage PI with a small 5'' mono coil for mainly river detecting a couple of locations that mums and kids visit during the summer months,main reason is that some of these mums have grannies high quality lumps of ice on the fingers and when wet of course they are lost,but the Mirage with the small coil which does have a fine gold setting is deadly is situations like this.

Also have a TDI Pro with both large and small Minelab coils mainly for inland use as i dont fancy using that for beach detecting and risk dropping it in the water,my other Pulse is one of just 13 ever made 'original' Crossbow detector made by George Overton from Geotech that is mainly designed for pure depth and runs Garrett SeaHunter coils,that detector is rare as anything and will never be sold neither will the other either.

The final PI which is scheduled to arrive the end of the month the mighty GPX that will complete my PI arsenal.
Still like using the Mirage though especially with that deadly 5'' coil on small gold jewellery.

Does Sevn make the mirage?

Dew, In reading up on the mirage last night, it was said that the mirage was Sevn's baby. Does anyone know what is the best power MOSFET to source the coil on a PI unit? In reading up I've found that I need the fastest cutoff recovery and lowest output capacitance to help in getting the delay time lower. I want to build two coils, one for higher delay time (silver) and one for lowest delay time (gold). I will need the best for the lowest delay. I'm using an IRF9640 for the higher delay.Thanks