How to approach making a coil for Infinium

[bbsailor]

Hi BB, ok the connector on the monocoil 8" is a 4 pin. I measured 77.8 ohms and 470 uH and 4.1 ohms at 285 uH. You are right BB about 2 coils, it has a transmit coil and a receive coil, after looking at a monocoil on the Garrett website they show this. Ok BB I will let you look this over. Thanks for the help. Oh I have an 18" spoked round coil housing from Hays. Back to you.

John Tomlinson,CET

John,

The 77.8 ohms at 470uH looks a little odd for just coil wire measurements. I suspect there may be some active or resistive components in the coil housing. If you get any additional information please post it or email it to me so I can better analyze the circuit.

bbsailor

[Wirechief]

Hi benhur, thank you very much and yes I would like to try and make a larger coil for my Infinium. I appreciate it and happy hunting!

John Tomlinson,CET
John's Detectors

[benhur]

Mono Coil Infinium

HELLO WIRECHIEF

THE MONO COILS OF INFINIUM WORK WITH A INTERNS CIRCUIT .THEY ARE DIFFERENT FROM THE COMMON MONO COILS.
THEY POSSESS A RX AND TX AND THAT CIRCUIT SIMULATES A MONO COIL.
NORMAL MONO COILS DON'T WORK IN THE INFINIUM.
I WILL SEND YOU A SCHEMATIC OF CIRCUIT FOR YOU.
B EST REGARDS

BEN-HUR RIBAS
HUNTER TECHNOLOGY
METAL DETECTORS AND COILS

[Wirechief]

Hi BB, ok the connector on the monocoil 8" is a 4 pin. I measured 77.8 ohms and 470 uH and 4.1 ohms at 285 uH. You are right BB about 2 coils, it has a transmit coil and a receive coil, after looking at a monocoil on the Garrett website they show this. Ok BB I will let you look this over. Thanks for the help. Oh I have an 18" spoked round coil housing from Hays. Back to you.

John Tomlinson,CET

[bbsailor]

What's the advantage of the tin plated vs the silver plated wire?

Silver plated stranded wire is too conductive and does not break up the eddy currents that would be detected at at low delays. Tin plated stranded wire does break up the eddy currents into the individual strands which will allow for a slightly faster sampling.

bbsailor

[hobbes_lives]

1. Use tin plated (not silver plated) stranded Teflon insulated wire to equal the resistance of the stock coil.

What's the advantage of the tin plated vs the silver plated wire?

[bbsailor]

John,

Go to the Garrett web site and look at the technical article that depicts Garrett coils. http://www.garrett.com/hobby/techsup...searchcoil.pdf Note that some mono coils are actually two concentric coils that are close together with separate TX and RX coils.

Measure the resistance on each of the connector pin-sets. If the connector has 4 or 5 pins and there is resistance between two sets of the pins and the pins are not wired in parallel, that would indicate that two separate coils are being used.

1. Use tin plated (not silver plated) stranded Teflon insulated wire to equal the resistance of the stock coil.
2. Match the inductance of the 18" coil to that of the inductance of the stock coil.

If, in fact, the coil for this Garrett PI machine is a concentric coil, match the TX coil to the stock coil for resistance and inductance. The RX coil has a little more latitude for adding an extra few turns to improve the sensitivity.

Measure the stock coil and post your results.

bbsailor

[Wirechief]

Hi everyone, I would like to try designing and constructing an 18" round monocoil for my Garrett Infinium. I do not want to damage the unit while trying to accomplish this task. I know there are many different values and parameters to take into account. I have BB Sailors fast coil article which is very good. So what testing setup do I need in the initial stage of this project without using the Infinium until I get in the ballpark? Thanks everyone and happy building!

John Tomlinson,CET
John's Detectors