Can pinpointer detecting thin chain?

[kt315]

new PP for nupi to play http://www.ebay.com/itm/DIY-Kit-Simp...ht_5167wt_1150

[nick holas]

Hi all,
Thanks fabian for your reply, will try it.
Thanks.

[scrungy_doolittle]

I assume you have one of the olde sinclair computers? And by the way, the actual quote from the bible is "the love of money is the root of all evil". "the love of" is crucial

[Fabian]

Hi all,
I ve made nupi PP with" fabian pcb",i ve set voltage ,replacing bc560 by 2n3906(360°),L2 402uH, L1 1,703mH, L1+L2 2,876mH, i replace C4 by152 ceramic .
It don t work!
R1 is sensitivity setting pot?
Someone got an idea?
Thanks

Hi Nick Holas. There is an error in my PCB. The connections 1 and 2 of the coil are swapped.

The capacitor C2 MUST BE MKP.

I also had to put a 100k resistor in series with VR1 to work well for small differences in the inductance of the coil with respect to the original.

Regarding replacements, I used the same components as NUPI, I can not advise you in this regard.

Good luck,

Fabian

[nick holas]

don t know why

Hi all,
I ve made nupi PP with" fabian pcb",i ve set voltage ,replacing bc560 by 2n3906(360°),L2 402uH, L1 1,703mH, L1+L2 2,876mH, i replace C4 by152 ceramic .
It don t work!
R1 is sensitivity setting pot?
Someone got an idea?
Thanks

[ToddB66]

Can pinpointer detecting thin chain?

Hi Toddb66,


The distance between the coil and the battery is nothing special.
The distance of 19cm at the NUPI-PP is, because the point is where
the electro-magnetic field lines start to deform by the proximity of the battery
and so, deteriorating the Q-factor.


By the way,
the nupi-PP can also function as an off-resonance pinpointer, for who do not know yet.

regards, nupi.

Hi Nupi !


Thanks for explaining the reason you set the distance at 19cm between the electro-magnetic field lines and the battery of the NUPI-PP (to avoid deteriorating the Q-factor).

I wish you success in marketing the NUPI-PP.


Best Regards,
ToddB66

[WM6]

By the way, there is great progress with the hypodermic needle detector.
He detects now, a 26G at 11.5 cm and still discriminated a horseshoe.

Great achievement. Congratulations. Testing commercial devices I only got 1cm with Nokta Fors Gold.

[Qiaozhi]

Nupi - now there's only one left.

http://www.amazon.de/Schatzssuche-Metalldetektoren-Technik-Selbstbau-Gel%C3%A4ndeeinsatz/dp/3921608813

[Nupi]

Nice schematic, thanks. It is very Elektor-like.

Because I think you're interested, have some checked out for you.
He has copied the circuit from this book, of the library.
It seems that the book is still for sale. (See the pictures).
Too bad for me that I have the schematic received later.
I can understand that it is difficult for you to understand that smart people
sometimes think the same solutions. (or nearly the same solutions).
In this example three people, might be more, who knows?


By the way, there is great progress with the hypodermic needle detector.
He detects now, a 26G at 11.5 cm and still discriminated a horseshoe.


regards, nupi.


Jealousy is poison to the human soul.

[IMG][/IMG]

[IMG][/IMG]

[WM6]

Nice schematic, thanks. It is very Elektor-like.

[Nupi]

Not only pinpointer, but as off-resonance metal detector too - as we know from this old Whites design:

There are people who say what they think.
There are also people who insinuate things.
I only respect the first.

Here you have neither an off-resonance detector.
I forget which of the two I've copied, sorry!!

[IMG][/IMG]

[WM6]

By the way,
the nupi-PP can also function as an off-resonance pinpointer, for who do not know yet.

Not only pinpointer, but as off-resonance metal detector too - as we know from this old Whites design:

[Nupi]

Hi Toddb66,


The distance between the coil and the battery is nothing special.
The distance of 19cm at the NUPI-PP is, because the point is where
the electro-magnetic field lines start to deform by the proximity of the battery
and so, deteriorating the Q-factor.


By the way,
the nupi-PP can also function as an off-resonance pinpointer, for who do not know yet.

regards, nupi.

[ToddB66]

I know the vibra probe 560 only of video. I heard that they gave regular problems.
The nupi-PP detects a 9 volt battery at 19 cm, so that is the optimum distance
between the coil and the battery. If you make the distance smaller, is no problem.
He does something "nervous" at the start of the detection, but he can live with it!!
You can, the nupi-PP, set in any desired sensitivity from max.to zero.
Across the capacitors'm totally agree.
That is why I have often said that they should used, with the NUPI-PP, MKP capacitors
if you achieve the best results.


Good luck!


nupi

Hi nupi !

This is in reference to your post #444, on Page 18 of 18 (As of Sept. 3, 2014 10:42PM).

I am now building a PP using a Velleman Metal Detector Kit no. K7102 for the electronics circuit.

I made my first PP some years back, using instructions from Tom's Treasures Internet Magazine that used a Gardner Bender metal sensor GPD-902 (In-Wall Pipe & Wall Detector ) for the electronics, and glued the ferrite coil at the front end of a pvc tube (See attached photo.). I wasn't happy with the Sensitivity control thumb wheel ; similar to the problem experienced with the Harbor Freight Cen-tech Hand Held Metal Detector, item 97245, although I improved the ease of setting the Sens. on this unit by adding a larger knob w/ a set screw (Simple to do by pushing the larger knob onto the small-diameter standard knob and tightening the SS.) I used the RS 1/2 inch "Blue-Capped" knob no.274-403 that came in a carded 2-pack priced at $2.34 including tax in Nov., 2011.

For my next homemade PP , using the Velleman Kit, I'll be required to solder the circuit components and mount the board inside a plastic box, add a pvc tube either to the front or side of the box (I'll decide that after getting further into the project.) and I decided to add a Radio Shack Mini Buzzer no. 273-0074, 12VDC Piezo, 3.0 - 16VDC, 4.1kHz, 7mA in addition to the standard red LED to provide a sight and sound alert (There's a spot on the board for an optional buzzer ; RS didn't have the SV4/5.) (See attached circuit photo.) My current Velleman retro-fit PP will be more compact than the previous.

Now to the main focus of this post.

In your post #444 you said "The nupi-PP detects a 9 volt battery at 19 cm, so that is the optimum distance between the coil and the battery. If you make the distance smaller, is no problem."

If I interpreted you correctly, the optimum distance from the coil to the battery for the nupi-PP is 19cm (.3937 x 19) or 7.48 inches. That statement grabbed my interest ! Being an electronics newbie, I wasn't aware that the distance from the ferrite coil to the battery has a max-distance threshold for optimum PP performance. Could you expand on that a little to give me a deeper understanding ? That will help me decide on the length of my coil tube for my Velleman retro-fit PP.

Thanks a lot nupi .......you the man !

ToddB66

PS: I bought the Vibra-Probe 570 several years ago, right after it came out and have been very pleased with it, but wish it had a greater target reach.

[Nupi]

I know the vibra probe 560 only of video. I heard that they gave regular problems.
The nupi-PP detects a 9 volt battery at 19 cm, so that is the optimum distance
between the coil and the battery. If you make the distance smaller, is no problem.
He does something "nervous" at the start of the detection, but he can live with it!!
You can, the nupi-PP, set in any desired sensitivity from max.to zero.
Across the capacitors'm totally agree.
That is why I have often said that they should used, with the NUPI-PP, MKP capacitors
if you achieve the best results.


Good luck!


nupi