the best vlf metaldetector schematic

[Esteban]

Hi Geo

Yes, this is the Rebeks.

[Sasho- Bulgaria]

With audio discrimination. This schematic is with high temperature stability.

[Sasho- Bulgaria]

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

[Unregistered]

Hi,Sasho,
I expect from you to say now that the popular firms in Varna work with your schematics.Are you the inventor of warm water?

[Sasho- Bulgaria]

Dear „unregistered’’ from Varna. You invented warm water 15 years before. Then I gave you the first variant of this schematic. It is made with PN 4393 transistors instead CD4007. You still make it and earn good money.

[Sean_Goddard]

INCOMING!!! ***Dives for cover***

Please don't let this turn into a who invented what spat, this forum is not the place for that as I found out shortly after I first joined.

We come here to exchange ideas ( well I do, though mine are usually a bit dumb , but that's probably because the only time I open my mouth is to change foot) !!

[robert]

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...

[Sasho- Bulgaria]

The schematic works well with this generator also:

[sascho-bg]

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

[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 .

[Sascho-bg]

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]

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?

[sascho-bg]

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.

[Unregistered]

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.

[Sasho- Bulgaria]

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.