is it a "good" pinpointer ???

[Max]

Hi all,
I have a question:

Is a good pinpointer one that can detect 1 eur coin at 1 and 1/2 inch (3.5cm) maximum ?

Because if not I can launch it directly in the trash can ! (homemade with junk - no cost)

Best regards,
Max

[Max]

Seems not much interesting topic here !

[Northerntrowel]

I think it's good...

...for that a pinpointer it supposed to do!!!

My Vibraprobe560 vibrate at 1 " on a Canadien 1$(loon dollars).
I know ,others pinpointer can do better like 2" or maybe a little bit more.

So!,if your can detect at 1"1/2 and it is stable and it build from scrap,
I think it's very good.!!!

Put it in a box/tube and try it in a real hunt!?!

Good luck!
JF

[Anker]

My self-made pinpointer can detect a copper coin in 2,5 sentimetres in diameter at 12 sm.

[Max]

...for that a pinpointer it supposed to do!!!

My Vibraprobe560 vibrate at 1 " on a Canadien 1$(loon dollars).
I know ,others pinpointer can do better like 2" or maybe a little bit more.

So!,if your can detect at 1"1/2 and it is stable and it build from scrap,
I think it's very good.!!!

Put it in a box/tube and try it in a real hunt!?!

Good luck!
JF

Hi Northerntrowel,
nice to hear it will be good !
Not tested in the field...just mounted from junk parts :
-an lm358
-a single transistor
-a ferrite rod like little am radios
-a pot
-a small soundcer/buzzer (40ohm)
-some 0.3 wire
other junk like the above
This was a "pipe" finder project on an old magazine I found on local library here (they have a lot from different countries in the archive) ,I've little modified the circuit and obtained 1 and 1/2 inch stable.
Works at 1KHz (original was 1700Hz) and consumes only 2mA in silent mode.

Best regards,
Max

[Max]

My self-made pinpointer can detect a copper coin in 2,5 sentimetres in diameter at 12 sm.

Hi Anker,
wow ! It's a Pulse Induction type ??? Or have you a large (not ferrite wounded I mean) detection coil ???

I'm not sure my circuit is good in field searching...not tested yet. I've tested just on my workbench untill now.

Best regards,
Max

[Northerntrowel]

Hi there!

Hello! Max and Anker.

Normally, I use a pinpointer to know where is the coin in the hole.in the bottom or on the sides of the hole. If there is an old silver coin, I does not want to make a scratch.So! for this reason 1 or 2" is correct for the most of my hunt .
But! WoW! Anker you have a great pinpointer!!!12cm. I thing that if somebody has to dig large holes and that it uses a large shovel then your pinpointer would be more desirable.
Max,if you can post a drawing or a picture of your pinpointer.Maybe somebody here could interested to try it!!? Me the first!
Thanks!
JF

[Max]

here it is...

Hello! Max and Anker.

Normally, I use a pinpointer to know where is the coin in the hole.in the bottom or on the sides of the hole. If there is an old silver coin, I does not want to make a scratch.So! for this reason 1 or 2" is correct for the most of my hunt .
But! WoW! Anker you have a great pinpointer!!!12cm. I thing that if somebody has to dig large holes and that it uses a large shovel then your pinpointer would be more desirable.
Max,if you can post a drawing or a picture of your pinpointer.Maybe somebody here could interested to try it!!? Me the first!
Thanks!
JF

Hi,
don't know if there is some copyright about till now, maybe I've first to post to Carl before
I put something from magazines/other pubblications here... to first require some authorization
from the magazine/owner(s) (an italian magazine in this case).

Anyway, it's a very old circuit maybe from 1983 (maybe copyright expired ?) or so and
this is what about original and modified circuit.
Original purpose was a "in wall" pipe finder.
Original coil is 0.4 mm diameter magnet wire, 700 turns on ferrite rod, giving a freq.
of about 1700 Hz in the circuit.
One could use anything for T2, T3 just common pnp and npn types.
T1 is just a bit sensible and must be some good gain (say 200HFE min) npn.
Just one transistor in osc stage - very simple.
Tested old c51xx (unknown npn) and works, I found in the old am radio too.

I've modified the circuit this way:
- used a shorter ferrite rod found in same small old am radio
- wounded 1000 turns with 0.25mm wire and another with 0.3mm wire --> second works better
- something from 700 to say 1200 turns would be ok and wire from 0.2 to 0.5 too
- used a 22Kohm lin pot instead of 10Kohm --> if can't stop sounding use bigger value (47K, 50K, etc)
- used 470nF for C8 instead of 1uF

Circuit is very easy to operate. Just switch on and set a threshold on the pot...then
can detect easy 1 eur coin (loud) at 3.5cm.
It's not a Vibraprobe but seems working...and costs nothing !Only a 9volt battery required.

I think also depth could be improved a bit also. I have to enclose in something and try on test field search.

Best regards,
Max

[Anker]

Hi Anker,
wow ! It's a Pulse Induction type ??? Or have you a large (not ferrite wounded I mean) detection coil ??? Best regards,
Max

My pinpointer is of IB type. Detection coil consists of four ferrite rods put together. But more frequently I make pinpointers of Q-meter type, because they are more simple in construction and work. Such pinpointer's sensitivity is 9 sm for a coin of 2,5 sm in diameter.

[kt315]

But! WoW! Anker you have a great pinpointer!!!12cm. I thing that if somebody has to dig large holes and that it uses a large shovel then your pinpointer would be more desirable.

guys, I ask you to remember that you have VERY much famous pinpointer worldwide (your pride) because you are HERE. HERE is site of Carl Moreland. I re-present it for you - Hammerhead-PP
... my two cents to your chat.

[Geo]

I can't understand. Who is the better ???? Anker or Hammerhead ???
Maybe now is time for Robert or Sony

[Max]

But! WoW! Anker you have a great pinpointer!!!12cm. I thing that if somebody has to dig large holes and that it uses a large shovel then your pinpointer would be more desirable.

guys, I ask you to remember that you have VERY much famous pinpointer worldwide (your pride) because you are HERE. HERE is site of Carl Moreland. I re-present it for you - Hammerhead-PP
... my two cents to your chat.

Hi kt315,
that's true ! But my purpose was to test a traditional (made of junk) PP and just to experiment if suitable for a made of scrap pinpointer (the poor-man one!)...but if one have HH in smt is for sure a very good alternative.

Best regards,
Max

[Qiaozhi]

Hi kt315,
that's true ! But my purpose was to test a traditional (made of junk) PP and just to experiment if suitable for a made of scrap pinpointer (the poor-man one!)...but if one have HH in smt is for sure a very good alternative.

Best regards,
Max

A detection distance of 1" to 1.5" is good for a pinpointer. There seems to be little point (pun intended) in having a detection distance of 12cm (4.7").
I can imagine that this might be useful if you're wondering whether the object is buried in the side of the hole or at the bottom, but the usual job of a pinpointer is to "pinpoint" that very small elusive target.

[Carl-NC]

My studfinder-based pinpointer hits a US quarter (roughly 1 Euro size) at ~2". This is fine for coins. But I often would like more sensitivity, not for coins but for for small bits of metal that end up in the dirt pile. These are hard to get with the pinpointer. Maybe a Hi-Lo sensitivity switch would be good way.

KT, I like the HH pinpointer. That's on my long to-do list.

- Carl

[Max]

Hi,
have tested in my garden the "poor-man's" unit...seems it works. Used graphite shielded pipe to enclose this time. Seems no problems with static charges and capacitive.

In ground:
Detect easy at 1 - 1.5 inches detpth 1 and 2 eur coins. Not easy small pieces of metals like nails fragments or small oxided iron wire pieces.
Have to test in real search !

Best regards,
Max