Wednesday, November 22, 2017

A few thoughts on using large search coils

I often use a large 17 inch search coil on my CTX 3030 when I want to cover ground quicker and search for deeper targets.
There are plenty of reasons for using a large search coil, but ground coverage and target depth are the best reasons.
I have often changed to a large search coil on a site that is producing and found nothing more than I did using the standard size metal detector search coil, sometimes it does not make a difference.
A large search coil used in even a moderately trashy area may and often does cause you to miss good targets. 
You have to know why you are using a large search coil and why the search site is a good place to use a large search coil.
It all goes back to site selection and understanding the effects of both ferrous (Iron) and non ferrous target masking. 
A large search coil can cause you to walk over an area without detecting what you are searching for, a smaller search coil may have you digging like a crazy person over the same area.
So I look at large search coils like I look at pulse induction metal detectors, they are very site specific. 
Use a deep detecting large coil or PI at the wrong type of site and any target depth advantage quickly disappears, along with your chances of recovering anything good.
A large search coil will not change your fortunes if you are having a tough time finding anything, unless ground coverage and target depth are issues.
Again, site selection and understanding the effects of target masking will help you decide if you need to go large.
So too will knowing the recovery speed of your metal detector, or time it takes for your metal detector to recover and detect something after it detects a previous target. 
Once your metal detector threshold (Background noise) disappears you are not actually detecting anything until the threshold reappears which is a scary thought at a trashy site where you could have your search coil over multiple targets.
If you are thinking of investing in a large search coil, make sure you have the sites to get the maximum return on your investment. 





No comments:

Post a Comment