A VLF RECEIVER

[Alex]

Anybody has the time and patience to make a PCB from this
vlf receiver schematics? .I have a small idea to use it with other device
as a LRL .R4 is 22M and I cannot find so big value so I have to use 5 resistors in place...
Any help welcome.
thanks

Alex

[Alex]

here the schematic:

[Fred]

Hi,

this receiver has no tuning circuit, i´t s just a filtered amplfeir ?
So i guess you must connect it to a computer to "see" signals...
regards,
Fred.

[Alex]

Yes this is only filtering and amplify the signal up to 20 kHz .Is good for gold
and silver frequency.Of course you need a laptop to see the signal..also you can listen on the phone...Need other device too.
I have to make first this one after I will try and do experience outside..

[Fred]

Originally Posted by Alex

Yes this is only filtering and amplify the signal up to 20 kHz .Is good for gold
and silver frequency.Of course you need a laptop to see the signal..also you can listen on the phone...Need other device too.
I have to make first this one after I will try and do experience outside..

Hi alex,

From 0 to 20khz you are going to pick up plenty of signals, natural and not-so-natural , but i don´t see how you can detect any metal with it , and less discriminate between them.
anyway it could be an interesting experimentto to go around with a laptop and see what happens.If you detect a multi-thousand tons moving and radioactive metallic item, don´t be afraid it´s just a submarine.
Good luck,
Regards,
Fred.

[Alex]

Is ok.I ask something and until now you didn't answer me. I need the PCB. .I know I can hear a submarin even a angel .A good one .
You are a guru not me, so if you want you can add a fine tuning at this schematic for 5Khz and 8.7khz.
This can be your help in this project.Wait until the end....
I told you there is another device in this but we will talk later .First step build this ,make the improvment ..and see.