surf pi coil question

[woodbob123]

Advice needed on the number of turns needed
coil dia id 20cm 8" od 22cm 81/2" former 10mm wide former machined from thick walled plastic water pipe.
How many turns, can i use 7/0.2 hook up wire have several reels or do i need thicker wire & less resistance
can i use a single cable from board make coil and return to board, section above coil inside heatshrink cable.
would it be best to add a shield if so does it make a difference if it's connected to start or finish of coil.
no time to experiment my grandson's are waiting to find treasure lol. thanks

[silverdog]

You certainly can use 7/0.2 wire, whether it allows the delay to be set low enough to detect gold would need to be tested

I would guess at this late hour you would need around 24 turns ?

Some members have used a coil without shielding, I guess it depends on your hunting ground
If you decide to shield don't forget to leave a small gap, connect the shield to the pcb gnd

[golfnut]

I did 18 turns of 0.3mm enamelled ~ handspan diameter.

No shield - works ok - not fantastic.

Depth comparable with my IGSL efforts. About 5 - 6"



Hoping idx I ordered with 27 DD will get to 8" on mid size coin lying flat..



S

[woodbob123]

Everything worked out grandsons were delighted PI will keep them digging lol