Pinpointers TOPIC

[Gyur666]

Does anybody have something experience about it?

[ik5pwr]

Homebrew Pulse induction pinpointer

This is my project ,Pulse induction pinpointer 1 Euro at 6/7 cm compact and long probe version.

First test http://www.youtube.com/watch?v=SKnRRMh-dGE
Assembly http://www.youtube.com/watch?v=ueFmYIovjGg
compact & vibra http://www.youtube.com/watch?v=CwNmoFbAL6k

battery is a Litium 11,1 V connect at charger with multipolar share a
coil probe , led at bottom indicate when battery is low , at start is possible to choice silent mode led /vibration or buzzer (default)

sorry for my English

[Qiaozhi]

This is my project ,Pulse induction pinpointer 1 Euro at 6/7 cm compact and long probe version.

Are you planning to post the source code for this project?

[ik5pwr]

yes next days I share a basic routine in picbasic ...not a full source

[hobbes_lives]

Is U4 drawn correctly in the schematic, with the coil input to - and the feedback loop to + ? It seems that pins 2 and 3 are reversed, at the very least?

[ik5pwr]

...Collapse signal of coil feed inverting input of U4

[Eddy71]

Interesting P.I. MD, but for pinpointer lead battery 12V 7A/h not very large?

[ik5pwr]

no lead battery , lithium 11,1 Cell

[Gyur666]

Does anybody have something experience about it?

Nobody know Petra-Pin pinpointer? I'm going to build it. I think it is a simple way to make a two sensitivity, usable pinpointer.

[kt315]

guys, there is something you have to look on!

http://www.findmall.com/read.php?22,...00#msg-1365500

This is what the inside of a BH/Fischer pin-pointer looks like...and some air tests I did with it apart.
There is one pot lying flat on the board (DO NOT touch the other one), and it is to control SENSitivity...
you can mark the factory position of this with a fine tip perma-marker, then tweak it to try to get a few extra fractions of an inch...
You can desolder the LED and drill a hole in the case to mount it externally (the LED comes on with the buzzer sounding)
You can also go to Rat-Shack and get a louder (beefier) 6V buzzer (It looks the same as original, but is higher Decibel Rated)
A larger Buzzer or even LED will drain the battery quicker though (But it is worth it for the added audio and light for night hunting...
These are the only 2 mods I have done to this unit...OH!!! and you can add solder to the spots the coil is soldered to...glob it on...This seemed to add some distance, if only to give better conductivity to the coil???
Be mindful of the heat, as your dealing with small parts that can burn quickly...

[Funfinder]

Hello, I opened a new topic in the modification forum but you may be interrested, too:

http://www.geotech1.com/forums/showthread.php?t=17389

maximum detection distance: 20cm
pot - 20cm: 10cm
1 Euro - 24mm: 5cm
screw - 9cm long, 5mm thick: 3,5cm
small nail - 4cm long, 1,5mm thick: 3cm
little rusty metal piece - 8mm: 1cm

[Rolle]

Hello all!

I'm planning to build a new stronger casing for my old trusty pinpointer. In my opinion an ideal pinpointer should have a sharp tip so you can stick it into the ground and search for shallow coins even without any digging. For this reason I'm going to use a plastic (PE) 15 ml test tube ( http://images.daigger.com/view/1/dai...mages/4661.jpg ) as the blade of my new probe.

But here comes the problem: as the test tube is canonical and my ferrite rod is not, the ferrite rod is not fitting to the shape of the tube. As a result, I'm losing about 1 cm of depth because the ferrite rod is not in the tip of the probe.
What will happein if I just sharpen one end of the ferrite rod? This will make the tube and the rod to exactly fit each other, but will I lose even more depth because of the shape of the magnetic flux?

Thanks for your help!!


Here is a picture depicting the depth at the moment ( 5 euro cents)



And here is the probe with its old casing

[Skippy]

To sharpen or not - a good question. I would compromise and half-sharpen. I dont think you will gain too much from the extra 5mm of 'point', and if it turns out to be a disaster you can easily square-off the end of the rod again without much loss of length. Alternatively you could try glueing a small ferrite bead etc on the end of the rod - it might help a bit. Hope this helps.

[Rolle]

Thanks a lot!

Don't know how good contact there will be between the rod and additional pieces of ferrite, but testing how it works costs nothing (although I probably have to break down some old radios to get ferrite rods for testing )

Do I have to fine tune my pinpointer after I alter the length of the ferrite rod?

[Skippy]

I doubt any retuning will be needed, the pinpointer probably detects changes in oscillator amplitude, not small frequency changes. You could also try moving the coil along the ferrite rod to see if that slightly improves sensitivity, you just need to note the original position in case you have to 'restore' it. Good luck.