Can pinpointer detecting thin chain?

[Nupi]

Tomato fits better in ferrite ring or cap. You should try bigger diameter core and you will see some distance increasing.

I like the idea of long range pinpointers like yours because in many cases you can pinpoint target from the surface.

With regular pinpointer you have to dig holes an poking your pinpointer into it all the day.

You are absolutely right.

[Davor]

Simulation shows 15kHz. IMHO it would be beneficial to go up with frequency. In that case you should consider going for pins 4 and 9 instead 5 and 11. Right now the sound is a bit irritatingly high, so maybe 4 and 6 would be ideal with elevated frequency.
I made it work in LTspice the way it behaves in real life, only I did not hit the sweet spot with the working point yet. I think the feedback could be cranked up a bit to promote the super regenerative behaviour, because it does look that way. That would explain a lot about the sensitivity.
I also discovered that emitter degeneration resistor is a far more responsive component to tweak the sweet spot. Maybe this design would benefit ftom some serious bias redesign, but don't worry, it will remain simple.
Yeah, this is interesting!

[Nupi]

Simulation shows 15kHz. IMHO it would be beneficial to go up with frequency. In that case you should consider going for pins 4 and 9 instead 5 and 11. Right now the sound is a bit irritatingly high, so maybe 4 and 6 would be ideal with elevated frequency.
I made it work in LTspice the way it behaves in real life, only I did not hit the sweet spot with the working point yet. I think the feedback could be cranked up a bit to promote the super regenerative behaviour, because it does look that way. That would explain a lot about the sensitivity.
I also discovered that emitter degeneration resistor is a far more responsive component to tweak the sweet spot. Maybe this design would benefit ftom some serious bias redesign, but don't worry, it will remain simple.
Yeah, this is interesting!

Thank you very much for explanation and effort.
It is a simple but effective circuit.
I am very fascinates how much improvement you can make.
I'm going to bed. Maybe I speak you tomorrow.

[chemelec]

Designation		Frequency	Wavelength
ELF	extremely low frequency	3Hz to 30Hz	100'000km to 10'000 km
SLF	superlow frequency	30Hz to 300Hz	10'000km to 1'000km
ULF	ultralow frequency	300Hz to 3000Hz	1'000km to 100km
VLF	very low frequency	3kHz to 30kHz	100km to 10km
LF	low frequency	30kHz to 300kHz	10km to 1km
MF	medium frequency	300kHz to 3000kHz	1km to 100m
HF	high frequency	3MHz to 30MHz	100m to 10m
VHF	very high frequency	30MHz to 300MHz	10m to 1m
UHF	ultrahigh frequency	300MHz to 3000MHz	1m to 10cm
SHF	superhigh frequency	3GHz to 30GHz	10cm to 1cm
EHF	extremely high frequency	30GHz to 300GHz	1cm to 1mm

However, to simplify things about VLF a good idea would be to use term audio frequency range. Imagine doing a project covering 20 Hz to 20 kHz, it would be annoying to write ELF/SLF/ULF/VLF all the time. But again it would not be correct if you just write VLF because there is much more in that range. Right? Instead, simply use term 'audio frequency range'. As I said in the beginning there are already dozens of articles with wrong frequency designations and a good thing would be to correct and minimize mistakes.

[hadrianus]

Szia! Saját mutató.

https://www.youtube.com/watch?v=LrEy-YcM-i8

[Waikiki_Sweep]

OK! Instead of VLF lets name it audio frequency coil, audio frequency metal detector and so on. Terminology is not much important, understanding is.

I like Nupi pinpointer !!!!!!

[Nupi]

Szia! Saját mutató.

https://www.youtube.com/watch?v=LrEy-YcM-i8

Nicely done.

[Qiaozhi]

Szia! Saját mutató.

https://www.youtube.com/watch?v=LrEy-YcM-i8

Please read the forum rules -> Basic Rules of the Forums
and make your posts in English.

[Davor]

It is very nice!

[Waikiki_Sweep]

It is a great pinpointer and very nice documented project. I think also it needs a notes with explanation how electronic part works to let users to understand it better and fix it more easy if problems occurs. Thanks!

[Nupi]

Designation		Frequency	Wavelength
ELF	extremely low frequency	3Hz to 30Hz	100'000km to 10'000 km
SLF	superlow frequency	30Hz to 300Hz	10'000km to 1'000km
ULF	ultralow frequency	300Hz to 3000Hz	1'000km to 100km
VLF	very low frequency	3kHz to 30kHz	100km to 10km
LF	low frequency	30kHz to 300kHz	10km to 1km
MF	medium frequency	300kHz to 3000kHz	1km to 100m
HF	high frequency	3MHz to 30MHz	100m to 10m
VHF	very high frequency	30MHz to 300MHz	10m to 1m
UHF	ultrahigh frequency	300MHz to 3000MHz	1m to 10cm
SHF	superhigh frequency	3GHz to 30GHz	10cm to 1cm
EHF	extremely high frequency	30GHz to 300GHz	1cm to 1mm

However, to simplify things about VLF a good idea would be to use term audio frequency range. Imagine doing a project covering 20 Hz to 20 kHz, it would be annoying to write ELF/SLF/ULF/VLF all the time. But again it would not be correct if you just write VLF because there is much more in that range. Right? Instead, simply use term 'audio frequency range'. As I said in the beginning there are already dozens of articles with wrong frequency designations and a good thing would be to correct and minimize mistakes.

Imagine doing a project covering 3 Hz to 26 kHz.
How would you call it????

[Thomas]

Nupi Sweep?

[chemelec]

Data of the Pinpointer nupi.

Coins Don't mean Much?

Our Older Penny were Copper.
Our Newer Pennys are Copper Plated SOMETHING?
And NOW there are NO Pennies in Canada, DISCONTINUED.

Prior to 1967,Quarters and Dimes were Silver.
After that Older Quarters, Dimes and Nickels Were Nickel.
In Some Years they were Stainless Steel and other metals.

These Newer ones now are Only Heaven Knows metal.

[Nupi]

********** Rectification ********

The smallest chain link from the small chain of the video does not weigh 0.07 grams but only 0.007 grams. and detected at 0.5 centimeters.(air test)

[chemelec]

********** Rectification ********

The smallest chain link from the small chain of the video does not weigh 0.07 grams but only 0.007 grams. and detected at 0.5 centimeters.

I Can't Weigh that Small of an amount.

However, "Harp", Asked me This for my Pinpointer.

Distance (mm) of detection for:
Aluminum foil of chocolate: 3x3mm, 2x2mm and 1x1mm
Copper wire 0.4mm diameter: 3mm, 2mm and 1mm Lengths. (26AWG)

I Didn't do the Aluminum foil as I don't have any of it from chocolate bars.
But I Did do those Copper Wires and posted my results in my article.

Nupi, How well will your Pin Pointer do on these TINY Pieces of Copper?

However, Calculating it out:
Based on Weight of 1000 feet of wire, 1mm of 26AWG wire weighs .000143 Grams