Hi Andron.
I have found the Classic Mod 03 modified from you a very interesting restyling project.
I have some questions about it because I am Italian and I don’t know the Russian language.
I hope that you help me because I want to build this circuit.
The coils are not described in the schematic diagram.
Can you explain me which are the best coils to obtain maximum depth and sensibility ?
Is the TX coil made with two windings ?
Which is the diameter of copper wire ?
Which is the diameter of coils ?
Which are the value in ohm and in mH of the coils ?
Which cable is necessary to use to link the circuit and the coils ?
Which are the functions of R57 and R26 ?
Is necessary to regulate R58 to obtain 0V on pin 6 of U1 connecting pin 3 to ground ?
The I.C. U1 (OP177GP) and U7 (S-8054HN) are not available in Italian market.
Can I substitute them with others IC ?
Do you know others IC that works equal ?
After C9 there are three *. Denoted them something ?
Is C8.1 value equal to 68nF ?
Is C8.2 value equal to 33nF ?
Is necessary found the value for C7 experimentally ?
Before R47 there is a diode. Is it a led ?
If yes, can I use a red or green led with typical current of 10mA ?
Is it a light in add to sound ?
I see a capacitance before the pin 5 of U3-1 looking the schematic.
When is it used and which is his typical value ?
Have you developed a better software for U8 ?
Have you made a pcb ?
I am doing a large number of questions but I hope in your help.
Do not hesitate to tell me how if I can help you in something.
An answer will be very appreciated.
Thank you.
Best regards,
Cyberto