Can pinpointer detecting thin chain?

[Nupi]

The "polyethylene terephthalate" is not MKP but MKT.
MKT (polyethylene terephthalate) is not good for this. Only for plastic bottles.

For the stability, you need to use a capacitor MKP for C1 and C2.
Please read this website.
http://en.wikipedia.org/wiki/Film_ca...ilm_capacitors.

Please download the video I made.
http://www.filedropper.com/nupippmadeby

Regards, nupi.

[moruka]

Tomorrow I'll try and write, very thanks a lot
can laugh at me

[6666]

Hi Nupi some time ago you talked about that you made a full size detector and you would make a video of it, did you make the video ?
thanks

[Nupi]

Hi, 6666.
My son and I, have set up a Dutch metal detector company.
We are now working on a prototype and is an advanced stage.
The videos I will not post because it is a commercial product.
We will soon launch the comparison tests with 17 models metal detectors.

Regards, nupi

[moruka]

Hi Nupi, the stability is almost okay but a new problem has appeared, when I put the coil next to the ground the buzzer goes off. I think this is happening because of the ground balance. Can you help me deal with this issue?
If this english is better its thanks to my daughter who is studying spanish too.
Saludos

[Nupi]

Thanks your daughter from me.

This happens when the ground is mineralized, also in wet beach sant.
You need to tune the sensitivity to that sort of ground.
Place the pinpointer, with the coil close to the ground and adjust the sensitivity on the right point down.

Que tengais un buen fin de semana.

[moruka]

Hi Nupi
I did not understand what is the right point, thanks
no weekend work today
I wish much success of the project with your son

[Funfinder]

-5° @ Bulgaria... seems I have to go to Egypt at winter-time for treasure-hunting, or at least close to the black sea coast or mediterranean sea....
btw. since the dam-flooding of this sea around 7.600 years ago through the Bosphorus the black sea (before it was non salty water only) is a part of it but with its own special water situation (with well preserved finds and non salty water near the ground - you might wanna know this as a treasure-hunter).


Just for information:
Even the Garrett Pro-Pointer gives a signal if you hold em against a red brick-stone.
This is because it has no ground-balance,
it starts to beep or vibrate if the outside situation influences the internal EM-field strong enough
no matter if plus or minus field-values.
And I'm not shure if a Pinpointer should have ground-balance.
For extremly high mineralized soil it would give more sensitivity but on the other hand - well:
It complicates the work with the Pin-Pointer and usually such little helper will just point more closely
to the already detected find anyway - so it doesn't need "special powers" - while the find has been already detected.

What really works good for high sensitivity is a "direct EM-field situation adjustment" so if you switch on the PP
while it is already directly in touch with high mineralized soil it is set to the quiet zone
and ignores the mineralization but if it moves (still directly in touch with the soil)
closer to the find it recognizes that there is a metal object there.

This means "auto adjustment" and it makes a difference if you switch on the
pinpointer in air versus while its already sticked into mineralized soil or close to it.
The Garrett Pro-Pointer does this auto-adjustment every time fresh after switching it on.

And the coils shape of the Pinpointer also has to be useful so it can penetrate into the ground,
otherwise its more like a little ground scanning MD for small things that doesn't fits very good into digging holes.



Anyway, nupi - if your Pinpointer is really sensitive it has to find a 1mm soldering-tin ball or such
a small piece of 1mm wire if you hold it against the plastic housing, like a modified Garrett Pro-Pointer can
and I know from alot personal search experience that such kind of sensitivity level really often is needed!


Good luck to your business startup - I hope you will add more stuff to your available
sortiment of products because I guess you really have the potential, insight and knowledge
for the whole professional range if you start already such good with the "little" things.
But pinpointers are not "little" under real circumstances, they're around 20-35 % of the whole deal
and make treasure-hunting alot more effective and time-saving.

[moruka]

How many words
Already have termostabilost,C1 i C2 -culprit
should design housing

[Nupi]

Hi, Moruka.

For the right point, you can adjust the resistance R1.
You can Nupi pp also adjust so that it works as an "off-resonance", if you prefer.
This is set using R2.
R1 used to adjust the threshold.

Thanks for your kind words.
good luck, nupi.

[Nupi]

Hi, Funfinder.

Thanks for your kind words, I appreciate that.

Regards, nupi.

[Funfinder]

thx to you and the great constructive action, nupi.
btw. here's the brand-new coming soon Garrett Pro-Pointer AT - with 3 sensitivity levels:
http://www.garrett.com/hobbysite/hbb...r_at_main.aspx

[Nupi]

That looks very good, and also waterproof, beautiful.
The shape is almost the same as the previous PP. But why would you change, which is excellent!
Do you know what it costs?

[Polymer]

If you do not make good the coil may be that you are coming out of 100k
Khz area. I had better to advise 220k than 100k potentiometer.
But he now works.
Nice trip.
Regards, nupi

Hello Nupi,

I had a lovely trip thank you!

I didn't like reading that I might not have made a good coil, but I did listen and made a new one with a better winding technique.
Voila, it works much better and the adjustment to null is now at 76.4 kOhm in air. Putting the effort into making the coil
really well is definitely worth it. These values are for one ferrite rod (not three) and the detecting distance is still incredible.

Thought this might be of interest to other builders of electronic circuits:
I have had stability problems with the pinpointer which drove me nuts. Adjust to null, wait a few seconds and then it starts: bip, bipbip, bipbipbip more bips
and then it would slow down again. This happened quite often. Even the finest multiturn potis did not help.

I did find out what the problem was and you'll all be laughing or not believing it ...
Sooo, what was happening while I was testing the pinpointer on the table in front of me? Any wild guesses?

Well, it turned out to be my own breath .
Yes, my breath condensated on the circuit board and changed the resistances for a while.
I must say that I live close to the sea, there is always some salt in the air, it's humid and the houses are not heated
here in the short winter which translates to 15°C inside, where your breath will condensate on anything ...

Northern Europeans with cosy heating and very dry air will not have this problem I assume.

Anyway, I will be putting a coating on the pcb after finalizing the nupi pinpointer to prevent condensation quirkies.

With kind regards, Polmer

[moruka]

I had the same problem with breath (warming) of capacitors.
After replacing with good MKP -stabilnostta available.
Thanks Nupi