Bigger coil, more energy?

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Hi Garikfox and this is a good question.

The short answer is not really - in terms of the windings in the coil. The detector requires a certain inductance and resistance from the coil for it to work correctly and no matter what size of coil it is the requirement is the same. The amount of turns will differ between the different size coils i.e: smaller coils require more turns to reach the same inductance and larger require less turns but the specifications are the same for the inductance and resistance required. Inductance is a function of turns and resistance is a function of gauge of wire.

The main thing that draws more current and drains power is the amount of noise the coil has to interpret and becomes audio for us to hear. the more ground noise, EMI, target noise etc the more the detector works and requires more power. I guess with larger coils they have to deal with more of all this due to their area so they may drain more current however a smaller coil is more responsive so again may drain more power than a larger one due to more response

If we placed an 18" coil vs a 6" coil on a GPX say and both had full batteries and they were still and no interference (quite environment) then they may just spend the same amount of time running or would be quite close in run time. BTW i have never tried this test but this is my thoughts.

There may be other circumstances and people who may have more information here but for me its more about amount of targets that drains power and not coil size.

I hope that provides some insight for you. :) 


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Hi Redz, Rx gain may contribute to power consumption but would be hard for most to see any difference. I would think the way it would consume more power is the Rx is now receiving more signals and therefore using more power through the audio circuit. From what I understand its the amount of targets/noise that the coil picks up which will determine power drain, that is considering both large and small coil are wound with the same resistance and inductance requirements on the same machine type.

My suggestion is try not to be concerned about the power drain of coil sizes when making a decision on what coil to use, base your decision on the terrain and possible depth of targets in the ground i.e: lots of small stuff shallow = small to medium coils : looking for larger targets in deeper ground = medium to larger coils

I hope this helps.


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