Can pinpointer detecting thin chain?

[Davor]

Not yet. However, a friend have developed a PCB for it so it will happen soon. I'm slow.

[ionut_mtb]

this is very good pinpointer, but to achive maximum sensibility need freqvent adjustment. without adjustment will still work, but the distance of detecting is smaller.
i also used it with 6inch coil, 50+50turns with coin distance 10cm perfect and also sensitive to small metals. i wait for the result of the automatic. great job nupi and davor!

[Davor]

In essence it is a solution based on old Whites AGC TR. It is great. The automatic version schematic is out there, but it is not tested.
I had some turbulent times at work and simply could not play more with detectors. Hopefully I'll have a bit more time now, and I'm itching to make something.

[ionut_mtb]

i will try to make a coil with 4ferite rod but i wait for the Lmetter.

[Nupi]

Keep us informed about your findings. Good luck.

[aliaf]

Hello everyone. Here I collected Pinpointer NUPI.
I can not insert a picture, tell me how to do it.

[Polymer]

Just to put the information out for reference ... on this great pinpointer.

The smallest things I have found in real digging situations with the NUPI PP other than iron specks:

Lead shot, diameter ~ 2.2mm, approx. 0.06 grams or 1 grain. Detecting distance 7-9mm.
Hard to find, even if its right in front of your eyes

Have a nice day!

[ionut_mtb]

isle of pines, new caledonia. i dont have small findings. it was very nice.

[Polymer]

[ATTACH]33011[/ATTACH]
isle of pines, new caledonia. i dont have small findings. it was very nice.

Nice to see your type of finds.

What are are those nine flat-ish lead looking things ???

[ionut_mtb]

lead bullet... not sure

[6666]

Hi ionut_mtb
they look like lead projectiles,
I was on Isle of pines twice last Sept / Nov last year 2014
beautiful place, would loved to have had a MD with me.

[ionut_mtb]

i'm working on cruise ship(carnival legend). i i've been almost everywhere, but isle of pines... amazing!

[6666]

Hi ionut_mtb
Great job you have, very hard work if you are crew, I was there on Pacific Jewel and Pearl, NEXT time I'll pack at least the pinpointer, and have a bit of a look on the beaches which are amazing to swim at.

[ionut_mtb]

yes is very hard, i have 5 months contract far from family and friends. i will try to make nupi for diving, i have few ideas and i will share after i will make. one for diving and one normal, for helping the big metal detector. i made surf pi pro, is very nice, stil have some issues wich i will put on the right area of the forum, but i'm glad is working. (resonable) i want to buy a comercial MD so i can register in my country. home made MD cannot... i need invoice for register. i was thinking for teknetics eurotek pro DD11inch since i'm beginer in this hobby.
good day!

[Polymer]

Hmmm, not much happening on this thread, NUPI - I hope you are doing well!

I have been using the NUPI PP out in the field a while now and ran into a very annoying situation.
The PP would be "out of range" and could not be externally adjusted to the most sensitive point anymore.
My original tests inside and outside were fine before. I have now found out what the "problem" is.

I have a very sensitive NUPI Thermometer now
Heck, my original testing was done when inside temperature = outside temperature.
It took me a while to nail this bugger down, I thought it was maybe magnetic or something going wonky with the pcb at first.

I did temperature testing in relation to the most sensitive point from 0°C to 50°C with the adjustment pot.

Gosh was I surprised
I have an offset of 480 Ohms per °C for the 3 ferrite PP and
340 Ohms per °C for the single ferrite one!
It looks linear to me.

I would have liked to have used a linear PTC resistor as a quick easy fix.
Finding PTC Resistors with such a high temp. coefficient was not easy
or putting many in series is out of the question, because the
base value would be to high to use in this circuit. What a bummer.

I have now opted to have two external pots, same one for fine adjustment (2k) and one for
temperature adjustment (25k).

Does anyone else happen to have this problem?

I still highly appreciate the NUPI PP, especially for its simplicity, depth of detection and changing beeping frequency to depth/size of target.

Temperature drift seems to be an issue in electronics, but I couldn't find all to many posts about it here.

Happy Tinkering.