Can pinpointer detecting thin chain?

[Qiaozhi]

Nupi - now there's only one left.
http://www.amazon.de/Schatzssuche-Me.../dp/3921608813

[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.

[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

[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

[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

[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

[nick holas]

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

[kt315]

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

[bernte_one]

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

build it together yesterday
circuit works but in fact it is a sprial pcb coil the distance is to low
plan was a bigger sprila coil 10cm+ or a ferrit core coil

but you need to change the caps than to use a better q-faktor coil
works better with 9v+ and it make sens to use a 100r multiturn trimmer

regards

[bernte_one]

@nupi

if you need the book from gatowski please send me your e-mail via pm

[Polymer]

I've been on an intensive working stint the last 2 1/2 months and have time again to frolic in building stuff and posting, yay.
I built the NUPI PP yesterday as to Nupi's excellently depicted "recipe" and it works , but .


I am amazed and impressed at the pinpointing distance but have an audibly annoying constant tone at around 4.8kHz.
How do I get rid of that?

Also, when my hand approaches the multiturn pot for adjustment the beeping frequency already changes!?????
This also happens when I touch the battery. What can I do about this?

Finally, when a metal object gets closer than 1 1/2 inches to the ferrite bundle (after beeping rapidly) the annoying whine at 4.8kHz AND the beeping is gone. Silence.
Taking the metal object away again, it returns to "normal" again. What does this mean or is some thing wrong?

Hoping for enlightening insights ... Have a nice day or night ... Polymer

[Nupi]

I've been on an intensive working stint the last 2 1/2 months and have time again to frolic in building stuff and posting, yay.
I built the NUPI PP yesterday as to Nupi's excellently depicted "recipe" and it works , but .


I am amazed and impressed at the pinpointing distance but have an audibly annoying constant tone at around 4.8kHz.
How do I get rid of that?

Also, when my hand approaches the multiturn pot for adjustment the beeping frequency already changes!?????
This also happens when I touch the battery. What can I do about this?

Finally, when a metal object gets closer than 1 1/2 inches to the ferrite bundle (after beeping rapidly) the annoying whine at 4.8kHz AND the beeping is gone. Silence.
Taking the metal object away again, it returns to "normal" again. What does this mean or is some thing wrong?

Hoping for enlightening insights ... Have a nice day or night ... Polymer

Hi, Polymer.
It looks like an "earth" problem.
I try small circuits as Nupi pp out on a breadboard or solder it as a
dead bug styl. If everything works well, I solder it on a board.
This is for me the quickest and easiest way to experiment with circuits.
Also useful to detect errors.

Regards nupi.

[Polymer]

Thanks for your reply nupi.

I don't get what you mean with "earth" problem.

Anyway, here is a photo of my setup on a strip-board and the coil.

Perhaps you can tell me more after seeing it.

With kind regards, Polymer

[Nupi]

Hi Polymer,
sorry for the "earth", I mean the "ground".
It may be that you have a bad ground contakt.
It is hard for me to check the circuit from the picture.
You have to put closer together the windings of the coil.
Have you checked the voltages according to the schematic?
regards, nupi

[Polymer]

Nupi, thank you - The ground/earth problem is solved.

I made a new stripboard layout with different grounding geometry and
the problem of "sensitive to touch" is now gone.
Still have the horrible 4.8kHz whine in the speaker though ...

regards Polymer