Whites Surf PI schematic

[nelson]

Hi Dirceu, so if you made the radial coil, how did you place the shield?
In my case i used alusa foil with good results. So now when i finish the radial coil, i think i will just wrap the coil with alusa. What do you think?
Kind regards
Nelson

Hi! NELSON

I made my coil with 19cm ID cause is more sensitive at small objects presents at beach(jewelry). You can make large coils respecting the resistence and Inductance as I said. OK! my friend??

Best regards
DIRCEU

[DIRCEU]

Hi Dirceu, so if you made the radial coil, how did you place the shield?
In my case i used alusa foil with good results. So now when i finish the radial coil, i think i will just wrap the coil with alusa. What do you think?
Kind regards
Nelson

HI! NELSON

Give me other e-mail. I don't like outlook express.

DIRCEU

[nelson]

Hi my friend i had just reply your private massage.
But i can give another email too, this is [email protected]
And my main email is [email protected]
Regards
Nelson

HI! NELSON

Give me other e-mail. I don't like outlook express.

DIRCEU

[Gyur666]

I did a funny experiment. I made a coil from 0,4 insulated cable ( utp).The coil 23 turns 20cm diameter. 1euro and 1 euro cent I tried it. It 2-3cm better reasult, than same coil from cuzz wire! It means the problems is capacities of coil and because of this good the flat coil, because less additional capacity arises there.

http://www.66pacific.com/calculators/coil_calc.aspx

(not the best calculator) the best result of induktance, onto 1-2 cm of depth

[DIRCEU]

Hi my friend i had just reply your private massage.
But i can give another email too, this is [email protected]
And my main email is [email protected]
Regards
Nelson

Hi! NELSON

Do you received my E-mail???

Regards
DIRCEU

[nelson]

Yes Dirceu, i has just send you an email.
Many thanks
Nelson

Hi! NELSON

Do you received my E-mail???

Regards
DIRCEU

[DIRCEU]

Hi! NELSON

How is your work with SURFMASTER???

Regards
DIRCEU

[nelson]

Today i finish my radial coil. This is 185.8 uH and 1.2 ohms. Just tested on my lab and results are not to good jet. Tell me did you change the dumping resistor value?
Regards
Nelson
PD the coil is 19 cms, 22 turns

Hi! NELSON

How is your work with SURFMASTER???

Regards
DIRCEU

[DIRCEU]

Today i finish my radial coil. This is 185.8 uH and 1.2 ohms. Just tested on my lab and results are not to good jet. Tell me did you change the dumping resistor value?
Regards
Nelson
PD the coil is 19 cms, 22 turns

Hi! NELSON

Yes! the definitive value for dumping resistor is 370 Ohms (for me).
Put a trimmer instead of resistor and adjust for obtain max distance from target.

Regards
DIRCEU

[nelson]

Ok, so just a small diference from 390 ohms to 370 ohms, correct the sensitivity.
Is good to know that. I will experiment with a trimmer, take the best resistance value and then replace with correct resistor.
later i will let you know my results.
Thanks a lot and have a nice day.
Kind regards
Nelson

Hi! NELSON

Yes! the definitive value for dumping resistor is 370 Ohms (for me).
Put a trimmer instead of resistor and adjust for obtain max distance from target.

Regards
DIRCEU

[Gyur666]

In my experiences there are some interaction among coil parameters, cable, capacitor (1000uF) and dumping resistor. For example I tried 4000uF and gave a bad result. Maybe need to change the offset. It’s very difficult.

[nelson]

Hi Dirceu, i just made the coil you did, and star to play with trimmer has a dumpping resistor, selecting values from 280 to 450 ohms and the detector works good btw 310 and 400. Sencitivity noted smal increments,but never has you got. Best performance was 360 ohms, a 1.8 cms compper coin was detected at 22 cms, this on my lab, i don´t know if results may be beather wint the unit assembled and on the field.
By the way i ll make another surfmaster to see if i can get beather on it.
Regards
Nelson

Hi! NELSON

Yes! the definitive value for dumping resistor is 370 Ohms (for me).
Put a trimmer instead of resistor and adjust for obtain max distance from target.

Regards
DIRCEU

[DIRCEU]

Hi Dirceu, i just made the coil you did, and star to play with trimmer has a dumpping resistor, selecting values from 280 to 450 ohms and the detector works good btw 310 and 400. Sencitivity noted smal increments,but never has you got. Best performance was 360 ohms, a 1.8 cms compper coin was detected at 22 cms, this on my lab, i don´t know if results may be beather wint the unit assembled and on the field.
By the way i ll make another surfmaster to see if i can get beather on it.
Regards
Nelson

Hi! NELSON


Do You adjust the off-set trimer?
I change my magnetic earphone by one piezo and 220pF capacitor instead 1 kpF (C9 in original schematic).
All distances of targets related for me refers at final audio detection (only a small "click").

Regards
Dirceu.

[nelson]

What does C9?
Nelson

Hi! NELSON


Do You adjust the off-set trimer?
I change my magnetic earphone by one piezo and 220pF capacitor instead 1 kpF (C9 in original schematic).
All distances of targets related for me refers at final audio detection (only a small "click").

Regards
Dirceu.

[DIRCEU]

What does C9?
Nelson

Hi! NELSON

Does 15 us delay.

DIRCEU