How do novices make coils?

[vvki520]

Can I make a 30 inch coil for Safari?
What problems will I encounter?
Why does Safari coil have only two leads instead of four?
Who can draw a picture and tell me how to make this coil?：

[Emersonpaz]

Can I make a 30 inch spool for Safari? Measure the inductance and resistance and wind it so the values match
What problems will I encounter? Much depends on your knowledge of coils.
Why does the Safari coil only have two leads instead of four? must be mono, so only two single winding terminals

[vvki520]

Dear emersonpaz
Thank you for your reply
I began to be interested in DIY coils, but I only know simple electronic circuits. Can you help me draw the schematic diagram of the coil and tell me how to do it? I hope this request doesn't embarrass you, my friend emersonpaz

[Carl-NC]

Are you talking about the Minelab Safari?

[vvki520]

Are you talking about the Minelab Safari?

Yes, very lovely Carl
If this is not allowed, please let me know

[Altra]

I made 12 inch coils for the E-trac which I believe is the same specs as the Safari.

TX coil 560uH 0.6ohm RX coil 500uh 6 ohms.

@Emersonpaz - The coil is a DD and has four leads. Uses dual coax

Should be a DD coil and not concentric. Concentric will have ringing problems I can't tell you how many turns to use. The tx coil should be made with #20 Awg gauge stranded wire with pvc insulation. Or #20 gauge equivalent Litz wire. The RX coil is less critical and can be made with thinner gauge wire. On a large coil you can probably wind equal number of turns on the TX and RX. These coils are broad band and not tuned. It is important to use dual coaxial cable, such as S-Video cable. Or salvage a minelab cable.

You will have a hard time housing and shielding a coil this size. Not a beginner project, unless you like a challenge.

[Carl-NC]

Yes, very lovely Carl
If this is not allowed, please let me know

I was just confused when you said it only had 2 leads. I think Altra cleared it up, it has 2 small coax leads, so 4 wires overall. I agree with his suggestions and warnings. A major problem with a 30" coil will be sufficient rigidity, DD coils are very sensitive to coil movement. You could build a concentric which is more stable to impact but requires careful spacing between the RX coil and the bucking coil. It would be an advanced project.