Surf PI Pro

[ionut_mtb]

Why so serious? I'm asking, because i want to know is that synchronized clock signal important to circuit (performance / reliability) and why silverdog's version doesn't have it. If this is too much for asking, maybe i need to stop posting at all for this forum.

silverdog version is surf pi, and does not have sync osc. Surf pi PRO, has sync osc. and gain control.

[ionut_mtb]

only use piezo headphones...as i made a mistake a few months ago and used very low impedence headphones and now two of my surf pi's are faulty and unusable...so im left with only one working detector...i have some projects to do during the winter so ive got so much now to contend with

As my surf pi is not complete project to use outdoor, for testing i use only low impedance headphones, and, until now i had no problems. In vallon thread for using low imp headphones people use transformer 600/8ohm. maybe your problem is not from headphones, what could go wrong?

[dbanner]

I think the synchronization is to reduce noise from power supply in the main circuit?

[dbanner]

I used small output transformer in my surf p.i build and boy was the volume loud! I did have to re-adjust the damping on coil a little though.

[ionut_mtb]

I used small output transformer in my surf p.i build and boy was the volume loud! I did have to re-adjust the damping on coil a little though.

What have to do the damping resistor with the volume?

Loud volume is good for faint deep signals, but i need to find a solution to attenuate the loud volume on shallow targets, as it blow my ears.

[homefire]

Have a play at this circuit. I built a few before and they tame down the Booms and Bangs and add a bit of boost to the faint of heart.

[ionut_mtb]

Have a play at this circuit. I built a few before and they tame down the Booms and Bangs and add a bit of boost to the faint of heart.

Thanks for the schematic Homefire, i will give it a try when i will find my germanium diodes ). although i would like to see a difference between faint signals and loud signals. With this all sounds will be the same? it says: "will produce an even on-off sound"

[homefire]

There is variance in the loudness , just not as much.

[samii]

Cascading one more same transistor to original transistor solving audio problem of surf pi.
but if not adjust pot good speaker burning because of high sound.

[daverave]

As my surf pi is not complete project to use outdoor, for testing i use only low impedance headphones, and, until now i had no problems. In vallon thread for using low imp headphones people use transformer 600/8ohm. maybe your problem is not from headphones, what could go wrong?

not sure what damage has happened to my surf pi's using the low impedence headphones but one is now very unstable and lost a great deal of depth...im down to one working metal detector now until i can get these two detectors working...i should have fixed them by now but ive not been well lately with chest problem and depression...hopefully get things done during the winter months.

[Angelos]

i need some help...........i can detect all metals exept gold and only gold
any idea...plzzz your help....
5 cent 30 cm
1 euro 32 cm
3x3 cm aluminiun 45 cm
and
only 1cm 14k gold cross olso ring on center of my coil

helpppppppppppppp plzzzzzzzzzzzzzzzzzzzz

[homefire]

I would suspect your Sample Delay is just too long.

[ionut_mtb]

not sure what damage has happened to my surf pi's using the low impedence headphones but one is now very unstable and lost a great deal of depth...im down to one working metal detector now until i can get these two detectors working...i should have fixed them by now but ive not been well lately with chest problem and depression...hopefully get things done during the winter months.

Don't worry Dave, it can be fixed, when you are ready to start debugging just tell us what you get, we are here to help.

[ionut_mtb]

i need some help...........i can detect all metals exept gold and only gold
any idea...plzzz your help....
5 cent 30 cm
1 euro 32 cm
3x3 cm aluminiun 45 cm
and
only 1cm 14k gold cross olso ring on center of my coil

helpppppppppppppp plzzzzzzzzzzzzzzzzzzzz

Don't expect to much depth for the gold cross. You will need smaller and faster coil for that, beside the good setup of the pcb itself.

[Angelos]

thanks for your answers homefire and ionut.........final all good......gold cross a 18 cm.....
thank again for helping
coil..... 19cm 26 turns 0.4mm