Interview, David Johnson and John Gardiner

[Aziz]

It's 64 times voltage. As power, that's a factor of 4096. Not only is this basic physics, it is what you see happening on an oscilloscope when you actually measure it-- assuming of course that you understand what you're doing.

I know of ways to "beat the system" but I also know their pitfalls and that's why for now I don't do 'em.

--Dave J.

Hi Dave,

it's meant the coil current I (not the battery power of course). Don't we refer to the (TX) coil current, when we talk about 64x power requirement for doubling the detection distance? Anyway.

Well, I was believing the same (the 64x thing) until I made a true EM simulation using the numerical Biot-Savart simulation technique (via my own coil software). So it really depends on the case, when the power increase makes sense or not.
As you mentioned, there are many pitfalls using more power to the coil. But they can be solved to some degree of satisfaction.

What we can do easily today, is to increase the coil power by 2x or slighly more. Everything above 5x or even 10x is not practicaly. One need a very power efficient TX stage (>80% efficiency) to increase the coil current significantly.

The cheapest solution is still to reduce the EMI noise and rise the amplifier gain instead. Some coil arrangements like the anti-interference coils can gain a "power factor" of 10-20 times. That's a lot more instead of increasing the coil current actually.

To speak to the sceptics (who questioning my brave claim):
Everybody is invited to make their own (mathematical/physical) proof.

Cheers,
Aziz

[goldfinder]

OO

I use Open Office all the time for Text, Spreadsheets, Database, briefings, pictures, drawings. Fantastic package!

One of these days we'll get a deep seeking detector.

Goldfinder

[Alexismex]

Hello DAVE J.
I do not know if it is possible but i want to tell you an real true story that i have 35 years ago with two friends .... one a chief engineer of a very good Audio and TV industry and the other a audio ing ,....
In one moment we have a big discussion about the band width of a telephone cable that it was I M P O S S I B L E to send videos in this cables , no matter impossible !!!!!.....
....for sure in this time it was impossible but see now with another technique we are able to send video, audio stream, data etc.... at the same time in a very tiny telephone cable
That is a true story
And this story is the same for the density of memory .... and many things in Physics and electronics
Regards
Alexis.

[joecoin]

dig 10 holes a day easily

just use this

[simonbaker]

It's 64 times voltage. As power, that's a factor of 4096. Not only is this basic physics, it is what you see happening on an oscilloscope when you actually measure it-- assuming of course that you understand what you're doing.

I know of ways to "beat the system" but I also know their pitfalls and that's why for now I don't do 'em.

--Dave J.

Is one of the pitfalls increasing the Q of the TX coil resonant circuit, which can increase current without using proportionally more power?

-SB

[Dave J.]

The "rule of 64"

"Can we break through this wall?"
yes

"Is there really a market for an extra deep detector?"
yes

BTW, the 64 times power requirement for doubling the detection depth is a myth.


Any orders for such a detector?

Aziz

It's 64 times voltage. As power, that's a factor of 4096. Not only is this basic physics, it is what you see happening on an oscilloscope when you actually measure it-- assuming of course that you understand what you're doing.

I know of ways to "beat the system" but I also know their pitfalls and that's why for now I don't do 'em.

--Dave J.

[Aziz]

Hi all,

you will find an explanation and the formula for the 64x power law myth:

http://australianelectronicgoldprospectingforum.com/general-chat-and-discussion-forum/aziz-why-do-you-say-this/

It may help to understand it.
Aziz

[Wiltran]

Hi Gary - try OpenOffice or LibreOffice (both FREE), if you don't have Micro$oft Excel.
I've tested it with LibreOffice3, and it works fine.

I agree 100% with Qiaozhi, Openoffice is great, free and you can export PDFS!

[Aziz]

Sorry, the file did not upload.
I try again with the file zipped.

This magnetic field strength calculator is quite helpful.

Monolith

Hi Monolith,

yes indeed, this excel sheet may help to understand the basics.

So it does make sense, to increase the output power and the coil size because it's a quite cheap modification.

But there are further tricks to increase the detection depth as well.

Cheers,
Aziz

[Qiaozhi]

So Where is the Program to Run This "XLS"??????????????

Hi Gary - try OpenOffice or LibreOffice (both FREE), if you don't have Micro$oft Excel.
I've tested it with LibreOffice3, and it works fine.

[ivconic]

I don't agree with the ten holes.
Few people are capable of digging a single hole 3.5m deep in a full day's work, even in soft soil.
I agree on the accurate target identification at the newly reachable depths. This is very important and is still a solid brick wall.

But if the Wall of Berlin could be brought down, any wall can be brought down. Interesting that we are talking of a somewhat similar time frame.

Ah, and we have one amazing tool that was not available 20 years ago. The Internet. We now have access to datasheets and multiple brain power, spread around the world.

Monolith

[wam]

It is easier to check magnetic field

[moodz]

Its a spreadsheet ... use Micro$oft Excel

So Where is the Program to Run This "XLS"??????????????

[chemelec]

Sorry, the file did not upload.
I try again with the file zipped.

This magnetic field strength calculator is quite helpful.

Monolith

So Where is the Program to Run This "XLS"??????????????

[Monolith]

Sorry, the file did not upload.
I try again with the file zipped.

This magnetic field strength calculator is quite helpful.

Monolith