Whites Surf PI schematic

[daverave]

whatever you should still be able to get zero threshold...must be circuit fault or wrong component value

[multieagle]

I might add I'm using a shielded 300uH coil (measured at coil before coax connected). Coil is copper tape shielded with ground connected to the shield. The coax is shielded with multi-strand central conductor. The board ground wire is connected to the coax shield. The coil was designed for a different metal detector. I might add, nothing is overheating on the Surf PI board.

Any ideas?

[daverave]

you should be able to adjust threshold to silence...i can adjust both my 2 surf pi's to silence...i used linear pots

[multieagle]

Okay, my board is working and detecting. I have been watching videos on Youtube to get an idea what to expect. One thing I noticed is the Threshold/Tune variance. On my build, which has a guitar pot A254 (250K), I cannot reduce the threshold to silence. It has a constant background tone. The Youtube examples range from where mine is down to silence, with maybe a tick or two.

Not being an electrical genius, looked up the various types of pots and found the 254 variety comes in A & B. A254 is apparently logarithmic and B254 linear. If I change the pot to the linear variety would that make a difference in my threshold range? Or is my problem elsewhere? Or, is it normal for a Surf PI 1.2 to have this variance, depending upon build factors?

[bisba]

all you need attached
print 1:1
[ATTACH]27855[/ATTACH]
[ATTACH]27854[/ATTACH]
[ATTACH]27856[/ATTACH]
[ATTACH]27857[/ATTACH]
[ATTACH]27858[/ATTACH]

thanks a lot friend...

[bernte_one]

all you need attached
print 1:1
surfmaster2.pdf
surfmaster1.pdf
surfmaster3.pdf
surfmaster4.pdf
surfmaster5.pdf

[bisba]

do not despair there at the end of the tunnel start your work with that
http://md4u.ru/forum/download/file.php?id=10588

thank you my friend...

can you upload the pcb at jpeg format with correct dimensions please???
this pcb working 100%

[6666]

Search for 7zip unzipper program

[multieagle]

maxm3s, if your reply is in answer to mine (case shielding), I cannot open that type zip file.

[maxm3s]

do not despair there at the end of the tunnel start your work with that

http://md4u.ru/forum/download/file.php?id=10588

[multieagle]

Question: This may be covered elsewhere, if so please advise. I did a search and came up with coil shielding info. I want to enclose my surf pi 1.2 in a 2" ABS pipe. Have it pretty much planned out, and looks good. However, as it is plastic, should I worry about case shielding to reduce possible EMI? If so, would a graphite paint around the outside work? From searching, this is probably not a significant problem.

Secondary question: Must the PCB be grounded to the external shield?

TIA

[bisba]

i read the most of this thread but im comfuse with all post...

please the single side pcb and parts list

please help to find the edge

someone please

[bisba]

i read the most of this thread but im comfuse with all post...

please the single side pcb and parts list

please help to find the edge

[sinclairuser]

its all in this very thread!, search the thread, better still READ THE THREAD.
i'm not trying to be rude, and i understand its a long thread but sheesh.

[bisba]

Hi! CORDIUS

Many thanks.

I made SURFMASTER apberg's version and I used IRF9640.

Best Regards

DIRCEU ZANELLA

hi there...

my first post and i want to ask if someone can post the correct schematic and pcb for thiw project...i hear good results!
i made the lucas pi with good results and i want to make surfm...
please be sure for schematic and pcb please or some mods...
thank you for your time guys