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Title: Coil Information Post by: ysbytymike on October 19, 2011, 10:01:11 PM I've been trying to find information on coil frequency ranges in regard to effective detecting depths.
I currently have the 7.5kh 10inch DD. There is also a 18.5kh coil for my machine. I think I've seen somewhere, the 'lower' the frequency the greater the depth achievable. Is this correct? Mike Title: Re: Coil Information Post by: Chef Geoff on October 19, 2011, 10:12:59 PM Yes mike the rule of thumb is that the lower the frequency the deeper the signal will reach but the less sensitive it is to small low conductive targets, conversely the higher the frequency the more sensitive the coil will be to small targets but will not have the depth.
The 18.75kHz elliptical coil for the Xterra is a lovely coil to use and balances the machine back to how it was designed. Title: Re: Coil Information Post by: rjm on October 19, 2011, 10:15:32 PM The 7.5 you are currently using is a good all round frequency for searching. It will get most stuff competently.
The 18.5 khz is better for gold and thin hammered section coins and use with faster recovery speeds. The lower, 2/3/4. khz will go deeper on the larger items but have a slower recovery speed between targets. These frequencies identify iron easier and are better in mineralised soil. John Lynn (Norfolk Wolf) book 'Advanced Detecting' is an ideal read on the subject. You can get a free copy by ordering Treasure Hunting Mag on a years subscription. Title: Re: Coil Information Post by: ysbytymike on October 19, 2011, 10:25:48 PM Cheers Guys.
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