Maplin coil experiment

[kenny444]

Hello to all reading this. I am building/built a Surf PI ver 1.2 pcb and thought I may be able to use a pre made coil from another MD as a test rig. So I bought a Maplin L24BK coil and found the following, the 5 pin din plug has what appears to be two loops or two resistances. I have a new meter coming that will do LCR (inductance, capacitance and resistance), so although I cannot measure the inductance's yet I at least know where the assumed coils are connected. One set of pins measures approximately 12 ohms and the other 24 ohms.

I am also waiting for an open din socket so I can clip on and measure with more accuracy rather than juggling a plug and two test leads.

So may I ask please if anyone knows about the windings and if it is possible to tune the coil to the Surf PI using resistors in parallel or capacitors in series.

Thank you for reading this.

[6666]

On a quick search it looks like the Maplin L24BK coil is for a VLF machine so inductance is too high for PI.

[Qiaozhi]

As 6666 correctly states, your Maplin coil is not suitable for the Surf-PI.

[kenny444]

Thank you for the very quick response. Could I ask which if any of Silverdog's detectors may the coil be suitable. Would it be possible to use inductors in series? so the overall L would be seen as lower?. Grateful.

[Qiaozhi]

Thank you for the very quick response. Could I ask which if any of Silverdog's detectors may the coil be suitable. Would it be possible to use inductors in series? so the overall L would be seen as lower?. Grateful.

It is unlikely that the Maplin's coil will be suitable for any the stated projects, except possibly TGSL. However, it is not possible to be certain unless you actually test it. The first step should be to determine the inductance of each loop, which will give you an initial indication.

For the Surf-PI, you can either make your own mono coil (not very difficult) or buy a mono coil for a commercial detector, such as an original White's Surf-PI, Minelab PI or a Garrett SeaHunter.

[kenny444]

Thank you very much, the last recommendation is very useful information. May I ask please is there a list of coil head specifications somewhere or is this knowledge you have learned and saved, I hope my curiosity is not offensive. Appreciated. K.

[Qiaozhi]

Thank you very much, the last recommendation is very useful information. May I ask please is there a list of coil head specifications somewhere or is this knowledge you have learned and saved, I hope my curiosity is not offensive. Appreciated. K.

There is a list of coil parameters here ->
http://www.geotech1.com/cgi-bin/page...oils/index.dat
and a more complete list is attached (which I believe was originally posted by KT315).

[kenny444]

Thank you again, that is super information, I am very happy. My you find your hearts desire. K.