Can pinpointer detecting thin chain?

[Nupi]

Hello Polymer.

Good that you have solved the grounding problem.
The horrible 4.8kHz whine in the speaker is perhaps that the CD4024 is damaged?
Try the following: disconnect the coil, so that the oscillator does not work.
If the tone is still heard, you can almost say with certainty that the CD4024 is broken.
Otherwise, it is difficult to offer solutions through the internet.

BUT!! if you have used the parts that I have indicated, I can repair it free for you. (if you want).
You must pay only the shipping costs.

Regards, nupi.

[Polymer]

Thank you for your reply Nupi,

I have tried three different 4024 chips in the socket. Same results!
I measured the resistance of my trimpot just before beeping starts to see if the chips are different, just to see.
The tolerances amazed me, maximum at round 15% from bottom. Here they are:

MC14024BCP @69.1 kOhm
HCF4024BE @71.9 kOhm
HEF4024BP @62.5 kOhm

Another thing I observed is that the 4.8kHz whine is only on the green side of the tuning triangle.
Please see the picture.



Thank you so much for your offer of trouble shooting. Shipping from where I am now is expensive and a pain in the a***e.
I will be travelling the next few weeks but am not giving up on this yet. I will have sporadic internet access though.

Thank you, with kind regards, Polymer

[Nupi]

I have some tests done with the settings of the PP to mimic the problem.
It was harder than I thought. But just for the moment I wanted to edit the PP with a hammer, happened.
The horrible ??kHz whine in the speaker was there.
It is a wrong setpoint.The wrong setting is difficult to achieve, but you and me succeeded.
You have tuned exactly on the "tipping point". (4k8_whine.jpg)

Possible Solution: R1 and R2 pull out. Put a normal potentiometer instead. ( 100k.....220k)
and set the PP at the right point. Then you can always put a 1k potentiometer between for fine tuning.

A tip: you can from the point, L2, C1, R1 to the IC point 2-3-4-5-6-7-9-11 or 12 conect with in between a 1n capacitor.
This gives different detection tones and stability !!!
Worth to try it out.

Regards, nupi.

[Polymer]

HEEEY NUPI !!!! ..... It works now

I actually should be packing for travelling now, but I just couldn't wait to try this and I feel much better now!

My hammer has been saved a beating

The good adjustment point is at 106 kOhm - just out of reach of the 100k and 1k fine poti I had

No more whining! When turning the poti it seems as if I have two triangles as in the picture aka four possibilities of "tuning" points!?

Thank you, thank you, thank you!

I will try the different IC points after packing or else my wife will let me feel the hammer

With kind regards, Polymer

[Nupi]

If you do not make good the coil may be that you are coming out of 100k
Khz area. I had better to advise 220k than 100k potentiometer.
But he now works.
Nice trip.
Regards, nupi

[Funfinder]

A few days ago I found a thin chain with the DeepHunter and 45cm coil,
but only because of the broken cross.

First I only detected the "big" part of it, next the smaller piece and
later I had a very hard time to detect the very thin chain parts with
the modded Garrett Propointer, adjusted to absolute critical sensitivity.

For testing if the pinpointer really is able to detect such stuff,
bending some thin and very short wire-pieces, hooking them
together and mix this stuff with earth will work pretty good.

[gaby_sult]

Dear sir Nupi, I have watched with interest the scheme and explanations scheme yet you have managed to stabilize this pinpointer?

[Nupi]

Hi, gaby_sult.
How stable do you want the pointer.
He is quite stable.
I have, on video, for 5 minutes a stability test made of the nupi pointer, who had Nezocas made. The test was with a 5 euro cents on 8 centimeters, 3,2 inches away. In the 5 minutes it remained stable.
In an angry mood have thrown the video from youtube.
I tried, the schedule from Davor, without success, but it makes the simplicity of the pinpointer invalid.
regards, nupi

[gaby_sult]

Sorry it was my fault, I not see too well on my initials capacitor MKP or MKT.
That's when you retire you do not see very well.
Have a nice day and much health.
P.S. I am from Romania.

[Nupi]

It does not matter that you are mistaken.
We make all of us mistakes, sometimes.
Regards, nupi
P.S. I am from Spain.

[moruka]

Hello Nupi.I did your pinpoynter and got very good parametri.No have a problem, is not stable, and must reduce it by potentsiometar.Ne I shielded, but could this be related to temperature ,i need help. Please direct me on what depends on stability.Everything is done under the scheme.That may work, but it would be perfectly stable.Sori for bad English ...... ..google translate Regards for best scheme

[Nupi]

Hi, moruka.
It could be several things.
Have you for C-1 and C-2, MKP capacitors used?
Have you tightly wound the coil?
Is the potentiometer not ramshackle?
Have you not taken the pinpointer out of the freezer?
First, check all these points.

regards, nupi.

[moruka]

Hello NUPI
C1 and C2 =MKP
Coil ....little difference from the original-wire 0,4 for two coils(0,28 -not worked)
R4 and R5 =47 kom = voltage circuit(1Мом not worked)
haha freezer .......Bulgaria is -5 temperature
whether to do shielding?
PP detected 12mm. coins - 10 santimeter,perfekt
how achieved resistance coil....main coil -2,2om and 1,8 om
Regards

[Nupi]

It is strange that you have to use other values.!!!!!!!!!!!!

You can shielding but first the PP must work stably.
Can you measure the frequency of the PP?
What are the inductance values of the coil 1, 2, 1+2?
What a transistor you use?
Can you make a close up picture of of the PP?
What are you eating tonight?

On these video links can you see the stability from the PP.
Regards, nupi.

http://www.filedropper.com/nupippmadeby
https://www.youtube.com/watch?v=JnGYvs2gHvQ
https://www.youtube.com/watch?v=OvG9h2lsELU

[moruka]

Hi,Nupi
transistor BC560C,C1 and C2 - polyethylene terephthalate(http://mario.bg/shop/default.php?cPath=29_39)
inductance.......sori ,onli Got knows how
Yes ,perfekt work https://www.youtube.com/watch?v=JnGYvs2gHvQ
fight continues ......thanks Nupi
Ohhhh this english