Surf pi coil ?????

[godzirra]

Sir, you are a legend - and I now have a new site to haunt If Razorback comes through I will be back to post an update for anyone else who is building the same kit. Many thanks TH'r !

did razorback ever come through? if so what was the coil and how well does the coil work for you

[kt315]

this is conversion AWG in mm, although in russian, but clear.

[chemelec]

Interesting! How big is the diameter of the wire? 0.5 mm?

I used a 28 AWG wire.

[Dixix]

This Ferrite Rod Might be of Interest to some People here.
Winding 25 Turns on this Ferrite Rod Gives an Inductance of aproximately 250uH
(Or 40 Turns - 400uH, Etc.)

On my Prototype of the Surf PI, I can detect a 1/2 Gram Gold Nugget at about 1 1/2 inch.
A 1/8 Gram gold Nugget at about 3/8 inch.
Or my Gold Ring at about 5 Inches.

http://www.goldmine-elec-products.com/prodinfo.asp?number=G19561

Interesting! How big is the diameter of the wire? 0.5 mm?

[chemelec]

This Ferrite Rod Might be of Interest to some People here.
Winding 25 Turns on this Ferrite Rod Gives an Inductance of aproximately 250uH
(Or 40 Turns - 400uH, Etc.)

On my Prototype of the Surf PI, I can detect a 1/2 Gram Gold Nugget at about 1 1/2 inch.
A 1/8 Gram gold Nugget at about 3/8 inch.
Or my Gold Ring at about 5 Inches.

http://www.goldmine-elec-products.com/prodinfo.asp?number=G19561

[6666]

Ok thanks.

[TH'r]

As requested, they used a TDI type plug wired in the TDI configurtation. I think not a problem for them, they specalize in TDI aftermarket coils.

[6666]

TH'r
what type of connector did they put on that RG8 ?

[TH'r]

If you want to optimize your coil for finding small gold I'd avoid the use of RG-8 or RG-58 as both have about 26pf of capacitance per foot and capacitance is the enemy of coil speed. RG-62U has 13.5 pf of capacitance per foot and there are other options such as a twisted pair with thick PTFE aka Teflon insulation that can be better still. I would be interested to see what feed line Razorback is using.

Good Luck!

Dan

The cable on the coil Razorback made for me is marked RG 8X

[Geo]

hello geo

i dont believe that a cable is destroyed by the water pressure

Hi.
Before long time i tried a "fat" microphone cable at 4..5 m depth in the water and it shorting.
RG58 is more resistant than the microphone cable, but i want to be sure before i"ll try it at 25+ m depth.

[bernte_one]

hello geo

i dont believe that a cable is destroyed by the water pressure

[Geo]

Hello.
I want to make a coil for Surf_PI for underwater detecting.
It must work at 25..30 m depth (2.5 .. 3 atm pressure). I am not sure if RG-58 will work perfect at this depth or the pressure will destroy it.
Does anyone has the experience???

Regards

[baum7154]

If you want to optimize your coil for finding small gold I'd avoid the use of RG-8 or RG-58 as both have about 26pf of capacitance per foot and capacitance is the enemy of coil speed. RG-62U has 13.5 pf of capacitance per foot and there are other options such as a twisted pair with thick PTFE aka Teflon insulation that can be better still. I would be interested to see what feed line Razorback is using.

Good Luck!

Dan

[DigginOlz]

Sir, you are a legend - and I now have a new site to haunt If Razorback comes through I will be back to post an update for anyone else who is building the same kit. Many thanks TH'r !

[TH'r]

Razorback Coils made me a very nice 5 1/2" custom coil for my modified Surf Pi Pro. Check with them, they might save you much trouble.