Unbelievable Discovery - "singing metal"!

[Esteban]

Hi Esteban.
Can you give me the Van Oort's article??

Regards

I believe I have in Portuguese, scanned from old photocopy only. Will send you soon.

Regards

Esteban

[Geo]

I believe I have in Portuguese, scanned from old photocopy only. Will send you soon.

Regards

Esteban

Thank you

[Geo]

Esteban, do you know how to make the critical adjust at the Rob L. Brown proximity gauge???
I constructed it before 2..3 years but without very good results. If i remember good, it detected a coin at 7...8 cm only.

Regards

[Esteban]

Esteban, do you know how to make the critical adjust at the Rob L. Brown proximity gauge???
I constructed it before 2..3 years but without very good results. If i remember good, it detected a coin at 7...8 cm only.

Regards

First, the tank 10 nF capacitor need to be recalculated for to obtain better peak voltage in the oscillator coil. Maybe you need to disconnect the 1 K final adjust potentiometer for to make this test. A simple digital tester in AC can helps here. Also tuning capacitor must to be recalculated adding pF in paralell. 10 nF can be much, so connect 8.2 nF and adding 1 nF and some 100 - 200 pf, put a final capacitor trimmer and adjust at full. This is tedious job, but is the only method for to obtain resonance at full. Capacitance box helps here. Remember that cable of capacitance box adds pF. Measure the capacitors connected in paralell and try to found equal. If you obtain in your capacimeter a final value of 9.45 nF, for example, added 8.2 + 1.2, and measure various. Regarding tolerance, you can find of a group this value.

According Van Oort's article, the ferrites are better if the both are cutted from a large piece, so characteristics are equals.

[Geo]

Hi Esteban.
As i remember, i did not made fine tuning to two coils on the ferrites, so maybe when i will have free time to give it a try again.

Regards

[dfbowers]

This is no joke but very interresting:
If you hold an old horseshoe with endings down near the coils of your detector with good ears perhaps you will hear a very high but silent singing sound the metal itself produces! The Fisher 1266-X creates this effect with good signal, the Garrett Ace 250 only just a bit and Jeohunter nothing, so there are differences.

What kinda crazy resonance here's working?

Has the audio signal the same frequency the search-coils are using?

Perhaps this also works with other kind of "musical" metal objects having a shape that supports vibration.

Please tell me an explanation of that effect and if you can reproduce it.

Of all the crazy things. I was able to observe this phenomenon. Here's how I did it. I hung a horseshoe, open end down from the ceiling of my basement by piece of string. Then, I used a PI detector (Carl's HH in this case) and approached the horseshoe with the coil in a horizontal orientation. While varying the frequency from 800 to 2300 Hz, the horseshoe would "ring" just like dragging your finger across a wineglass, at maybe 5 distinct intervals. Interesting thing, it would resonate at different frequencies not alway higher as the detector frequency was increased.. Sometimes lower.. Works with really old rusty one too! It's not real loud but definitely audible. Has to be tuned JUST RIGHT..

[simonbaker]

Now I've got to find a horseshoe... I'm still looking for a euro...

[Funfinder]

quote from:
http://en.wikipedia.org/wiki/Mains_hum

Because the magnetic flux density is strongest twice every electrical cycle, the fundamental "hum" frequency will be twice the electrical frequency.

That's why it vibrates so high comparable with weak glass-harp tunes - if the detector uses 7kHz the domains of the ferromagnetic (and also ferri-magnetic - it also works with ferrites) affected by magneto- and electrostriction oscillate at 14kHz. And it's so silent because of the low milliwatt output radiation-power of the searchcoils.

see also:
http://en.wikipedia.org/wiki/Tweeter
under: Piezo tweeter (ferroelectric speaker)

[Funfinder]

@ WM6


03-29-2010, 09:38 AM #8
Quote:
Originally Posted by Qiaozhi

I tried the same experiment with two different horse shoes, and couldn't hear any ringing.


Of course, you are normal, without auditory hallucinations.


03-29-2010, 03:38 PM #10
Quote:
Originally Posted by Fred
Come on, this effect doesn´t seem so extraordinary, just the right weight and dimensions so it can produce some audible oscillation...

Agree Fred. We need only shoe from musical horse.
__________________



03-31-2010, 10:23 AM #19

Quote:
Originally Posted by J_Player

For non-believers, you could lay the horse shoe flat, and sprinkle some salt over it. then move the coil near and watch the salt move on the surface.


Fully agree. Solution can be "cum grano salis" or it is woodoo magic.



03-31-2010, 03:29 PM #21
Quote:
Originally Posted by Fred
I really don´t understand what this is all about.
Putting a piece of iron in front of a coil is one of the most usual experiments seen in school books.This is called a solenoid

Seems you dont believe in "Unbelievable Discovery - "singing metal"!"?


_________________________________


Where are your scornful and taunting pseudo-critical comments, WM6, now while we have the proof this phenomen exists?

You are so quiet! I don't know you in this condition...

I'm feeling really sorry about you but I'm much more enjoying my triumph over you, WM6 and your deft replys!


You wrote:
"Solution can be "cum grano salis" or it is woodoo magic."

No, it can not! And what you're dark brain thinks that can be a solution may be just a crazy illusion!

Where are your "auditory hallucinations" now?

If I were you I would think twice before criticising everything with stupid comments if you don't want that in the end it turns out that you're the one with "hallucinations" and much more stuff you title against others!


WM6, this was just the first proof how worthless your filthy cynism and criticism is and more will follow. Take on warm clothes, you started to mess around with the wrong person! What you're doing really is not funny, even if you might think so!

And I don't care what you will answer to this, because I have better things to do - as example enjoying your well earned defeat!

[WM6]

You are so quiet! I don't know you in this condition...

I'm feeling really sorry about you but I'm much more enjoying my triumph over you, WM6 and your deft replys!

Something new happen? Oh, your triumph over me - it will be new national holly-day.

I am quiet because I am in hearing "singing metal". So, please, do not make noise.