Can pinpointer detecting thin chain?

[Nupi]

Aaaaaaaah!
Would you measure the coil between L1 and L1a-L2 and between L1a-L2 and L2a and between L1 and L2a?

[Fabian]

These are measurements



L1 to L1a-L2 (0,35 wire) 1,9 Ohms - 2 mH
L2 to L1a-L2a (Two layers coil) 4,2 Ohms (0,28wire) - 2.5 mH
L1 to L2a 5,1 Ohms 3.4 mH

[Fabian]

Can you tell me the ideal values of each layer in mH and ohms? I will make a new coil.

[Nupi]

Okay, it seems that messages is delayed .
The coil is not good.
I think I made the confusion with pictures.

I'm going to change what images to make it clear. It may take an hour, okay?
nupi

[Fabian]

Ok. If you have time and desire to do it now, I'll wait.

Thank you VERY much for the support, Nupi.

Fabián

[Nupi]

Ok. If you have time and desire to do it now, I'll wait.

Thank you VERY much for the support, Nupi.

Fabián

Okay, Fabian Do not look at the old pictures, but only use this.
If you have any questions you can just ask.
nupi

[maxm3s]

which function of R1 and R2

[greylourie]

Okay, Fabian Do not look at the old pictures, but only use this.
If you have any questions you can just ask.
nupi

Hello nupi,

This is a good instructional picture. Nice and clear. Is there anyway we could make it easier to find ? Maybe start a Nupi Pinpointer thread ?

Anyway thanks for your work.

[Fabian]

Okay, Fabian Do not look at the old pictures, but only use this.
If you have any questions you can just ask.
nupi

Thank you very much, Nupi. I'm working on it. When the detector is running achieved, I will show the result.

regards,

Fabian

[Fabian]

Hi Nupi. I continue doing coils. I got the following values:

2.7 Ohms / 1.58 mH for L1

1.5 Ohms / .330 mH for L2

At the junction of R5 and C4 I measure 4.18v maximum

And the PP works "backwards". When it's working, approached a coin and stops ringing ... I suppose it's for the difference in resistance, Can that be the cause?. I think I need to get copper wire of different gauges to follow.

Any tips?

Regards,

Fabián

[Nupi]

which function of R1 and R2

"Simply explained" With R1 and R2 set you the bias point for the detection point in.
It is a class-C oscillator.Bias point moves as oscilation begins due to build up of
voltage across the emitter resistor.Bias point moves as a target whent too the coil.
The oscillator will draw more current and you get a voltage drop across R3 and is detected by the Ic.
There are several factors that play a role in the operation of the pp.
The theme (which seems) can you read on the page 34 of the interesting book "inside the metall detector"
from George Overton and Carl Moreland.
Maybe this picture better clarified.
nupi.

[Nupi]

Hello nupi,

This is a good instructional picture. Nice and clear. Is there anyway we could make it easier to find ? Maybe start a Nupi Pinpointer thread ?

Anyway thanks for your work.

I do not know what is better. To open as you say A new thread I have no experience. Maybe someone can advise me on this.(Qiaozhi?)

[Nupi]

Hi Nupi. I continue doing coils. I got the following values:

2.7 Ohms / 1.58 mH for L1

1.5 Ohms / .330 mH for L2

At the junction of R5 and C4 I measure 4.18v maximum

And the PP works "backwards". When it's working, approached a coin and stops ringing ... I suppose it's for the difference in resistance, Can that be the cause?. I think I need to get copper wire of different gauges to follow.

Any tips?

Regards,

Fabián

Swap with L1 and L2a and try again.
I wait
nupi

[Fabian]

Hello Nupi.

I rotated the wires, (Once again, I had already tried) and not working at all ... I can not understand what is happening ... I did the coil rotating in the same direction, the values of the elements are fine ...

some photos

[Nupi]

It all looks very good, excellent.
But I think that capacitor C2 is not a MKP but MKT (I hate mkt)
Put in series to R1 a resistance of about 100K if it does not workyou put two resistor 100K
series to R1.
Please try
nupi