Vallon VMH3CS Mine Detector

[Qiaozhi]

That Interesting Eric
Was That with the standard coil does the led or tone change with differant metals as i dont seem to be able to tell at the moment?.

cheers all please all keep up the good work.

Any news on how to flash these units yet?

There is no ferrous / non-ferrous discrimination on the Vallon. It's a PI, and therefore can only discriminate based on conductivity.

[kingswood]

Hi MdToday
Yes Thanks
The only Problem im having is The limitations on the discrimination setting and the limited tone that it gives, everything so far sounds the same but im not giving up yet, got a sneeky feeling this is very similar to the Garrett gatx and if im right this unit should be brilliant on the beach.

Go Get Them Hammerd Coins.

In my experience with the Vallon, it doesnt have the ability to discriminate metals....but, I have noticed that the Vallon screech does sound a bit different on different metals. I would not trust that though and would just dig every signal In regards the LED's, this is simply the strength of the signal and doesnt relate to what type of metal it is....

[Davor]

@Qiaozhi
Err... G. Paltoglou might object to this, although his method relies on the imperfection of PI that happens with Tx ON period being shorter than the Rx last sample time.
A certain company made a ritual out of it by creating silly Tx timing schemes.
Discrimination is doable with PI.

[Qiaozhi]

@Qiaozhi
Err... G. Paltoglou might object to this, although his method relies on the imperfection of PI that happens with Tx ON period being shorter than the Rx last sample time.
A certain company made a ritual out of it by creating silly Tx timing schemes.
Discrimination is doable with PI.

I wasn't referring to any designs by G. Paltoglou, or to any company that makes "a ritual out of it by creating silly Tx timing schemes". I was referring to the Vallon, which is a standard PI. By "standard", I mean that it works in a conventional PI manner ... although there's nothing conventional in the way it achieves the results that it does.

[Mdtoday]

If yours comes in a canvas bag, do not breathe the dust, the battery cap can be a bit dicky when you first insert the d cells
so switch the machine on, then slowly screw on the cap until the machine starts up, this gives you a better feel for how much
pressure the cap needs to make good contact, and how tight it should be.
The manual has a few strange comments in it and does not describe all the functions and processes fully in good english.

Hi 6666,

Thanks for the heads up on the dust and battery cap.
I can only imagine where these things have been.
How are you going with your unit, are you using it much?

Brian

[Mdtoday]

Hmm, sorry 6666, were you referring to asbestos dust in the canvas by any chance?

Brian

[6666]

Hmm, sorry 6666, were you referring to asbestos dust in the canvas by any chance?

Brian

MY reference was to the "unknown" desert dust that was thick in all the pockets etc, could be contaminated.

[6666]

Hi 6666,

Thanks for the heads up on the dust and battery cap.
I can only imagine where these things have been.
How are you going with your unit, are you using it much?

Brian

I have not had much time to use it, so have not found any gold yet.

[6666]

Err... G. Paltoglou might object to this, although his method relies on the imperfection of PI that happens with Tx ON period being shorter than the Rx last sample time.

Davor would you happen to have a link to his patent that describes his method please ? searching only seems to throw up a bunch of unrelated stuff, thanks.

[Mdtoday]

Thanks, yeah, you never know.

Brian

[TH'r]

If yours comes in a canvas bag, do not breathe the dust, the battery cap can be a bit dicky when you first insert the d cells
so switch the machine on, then slowly screw on the cap until the machine starts up, this gives you a better feel for how much
pressure the cap needs to make good contact, and how tight it should be.
The manual has a few strange comments in it and does not describe all the functions and processes fully in good english.

Look at post 649 where Eric links instructions for adjusting the battery tube. Mine was among the ones that the tube projected too far, and made the cap difficult to engage. Yours may not project far enough and thus making only intermittent contact with the cap.

[Ferric Toes]

I recently bought a VMH3CS which I am confident has not been opened since manufacture. This is based on it's very clean condition and that the circular date label is intact. I measured 1.5mm projection on the battery tube end, so I would take that as being the figure to aim for. With my prior experience in military airborne radar there are setting up jigs for everything and everything has a tolerance. I will now change the instructions to 1.5mm +/- 0.5mm, which is easily done with a workshop ruler.

Eric.

[Ferric Toes]

Davor would you happen to have a link to his patent that describes his method please ? searching only seems to throw up a bunch of unrelated stuff, thanks.

Just Google george paltoglou, metal detector patent, australia and you will have everything you need to know.

Eric.

[6666]

Just Google george paltoglou, metal detector patent, australia and you will have everything you need to know.

Eric.

Thanks Eric, the full expression narrows the search right down to what I am trying to find, cheers.

[Davor]

...I was referring to the Vallon, which is a standard PI...

Err... any PI emitting both polarities may hardly qualify as a standard PI. Adding the transmission charge kick, an interesting phenomenon indicating sampling waaaay within a flyback, a mH coil finding rice-sized pieces of metal, and a fact it works for hours on less than 2 pounds of batteries...
No. It most definitely is not a standard PI.
From such a machine you may expect a trick or two beyond the ordinary.