the best vlf metaldetector schematic

[aft_72005]

Hi Sasho,
I upload again your circuit and my question now:
1 -How much degree phase differences between pin 1 of ne5532 ic
And pin 1, out put of lm393 when diskr. Pot variable from minimum
To maximum?
2 - How much degree phase differences between pin 1 of ne5532 ic and pin 7,
Out put of lm393 when ground pot variable from minimum
To maximum?
Best regards.

Hi Sascho
I wating for my questions reply.
Best regards.

Detect 2cm coin in 35 cm in ground.This is stable.
В този форум повече няма да влизам.Нямам намерение да гледам простотиите на откачени руски пияндета които обиждат българския народ.
Сашо

hi sasho
i wnat make a pcb for this detector.please help me about this.what is the performance of your detector? can detect a 2cm coin in 50 cm in air?35 cm in ground? is this stable?
thank you.

[aft_72005]

Hi Sasho,
I upload again your circuit and my question now:
1 -How much degree phase differences between pin 1 of ne5532 ic
And pin 1, out put of lm393 when diskr. Pot variable from minimum
To maximum?
2 - How much degree phase differences between pin 1 of ne5532 ic and pin 7,
Out put of lm393 when ground pot variable from minimum
To maximum?
Best regards.

[Qiaozhi]

Hi Sean Goddard .
Do you mean the follow schematic for Nexus?

This is not the Nexus. It's some other Bulgarian detector.

[Geo]

Hi Sean Goddard .
Do you mean the follow schematic for Nexus?

To Sean Goddard:
I was "Unregistred"
I can send yon my old good working schematic which is similar to “Nexus”.
Synchronous demodulator is made with PN4393 transistor.

To Sean Goddard:
Sorry,bad englich.
The diode synchronous demodulator work badly in signal level over 1.5-2volt.That is why the signal level has to be minimal. Amplitude detector shows that. The depth is result from the high oscillator amplitude and coil configuration.
The diode synchronous demodulator is not used nowadays.

To Sean Goddard:
The diode demodulator work badly in signal level over 1.5-2volt.That is why the signal level has to be minimal. Amplitude detector shows that. The depth is result from the high oscillator amplitude.

[Sean_Goddard]

OOPS repeated posting SILLY ME!!

I remember the diagram that was supposed to be the nNexus used a diode demodulator NOT a synchronous demodulator. This would be a good idea as it wont overload and thus you can crive as much signal into the ground as you wish. What it measures is change from the norm, rather than absolute signal level. Maybe this is how Georgi gets the depth?

To Sean Goddard.
Those kind of detectors was made 30 years ago in Bulgaria. I don't have information about the Nexus schematic.

[Sean_Goddard]

Sorry, it was my fault. Here is the correct part of the schematic:

I was sent this a year or two ago and was told by a VERY reliable source that it was the "Nexus" machine. Certainly the coil configuration would agree with this, but SOMEHOW I feel soneone is going to point out otherwise. I'd be interested to find out more. SOMEWHERE, someone has a Nexus schematic..Maybe .

The oscillator is pucsh-pull schematic. It is invented by Hartley.

The schematic works well with this generator also:

Yellow's....


Yellow's !!! Turn to green!
I invented everything so far.....so everybody just copying me!
Ha,ha,ha!
Anyway......good to see some spirit here!
bye,bye...