Hello I want a two-tone metal highlighting circuit for VLF to be installed on all VLF devices

[Aedell]

Hi I want a two-tone metal distinguishing circuit for VLF electromagnetic metal detector so that I can. Mounted on Admiral, IDXPRO or SMW555

[kt315]

Gold Mountain Tech KING COBRA has two tones.

[Carl-NC]

ITMD3 shows the details of a a 2-tone circuit and also the concept of a multi-tone circuit.

[Skippy]

On that GMT schematic, is the audio tone generated by the 7660 negative voltage generator, and the pitch of the tone determined by switching different caps on the 7660? Seems a little odd, 220uF in series with 120pF ?

[kt315]

btw i got FIRM diggest of the schematic. no mistakes. thank you Ted for them again.

[Skippy]

Thank you for posting that schematic, KT.

[kt315]

Thank you for posting that schematic, KT.

welcome. you will see left firm lists in the Archive. https://drive.google.com/file/d/1P4a...usp=drive_link
folder from ted.

[Aedell]

btw i got FIRM diggest of the schematic. no mistakes. thank you Ted for them again.

Do you have a printing chart

[kt315]

I have 50 pieces for selling. or do you want GERBER files to pay nothing?

[Aedell]

I'd like a plan, please.