Darryl, Either the concentric or DD should be easy to pinpoint with. Just a matter of taking a different approach with each. On the concentric coils, the "strongest" signal should be when the target is in the center of the coil. You can determine this by Xing over the target from a variety of directions, while in your "hunt mode". Or, you can use the Pinpoint mode and listen for the strongest response, while sweeping over the target. Or, if you have the X-70, you can switch to Prospecting mode and listen for the strongest response while sweeping over the target. Any of these methods should work fine for concentrics. With the DD coils, I still simply X over the target from multiple directions, making a mental note of where the strongest signals are located. When you cross over the target in a perpendicular sweep, the intersection of that X will be the location of the target. Many folks implement a sweep and drag method on DD coils. To accomplish this, simply sweep the coil back and forth (repeatedly) over the target, while pulling the coil slowly closer to you. When the signal finally "drops off" the front of the coil, that is where the target will be located...... directly off the front tip of the coil.
As to DD versus concentric in depth comparisons....... much of that will depend on your soil conditions. I hunt in what I consider to be moderately mineralized soil. I can typically GB with a setting of between 35 and 45. In those sites, the concentric coil will provide me as much depth as the DD. I just have to be more aware of overlapping my swaths to a greater degree. If I am hunting a site that requires a GB setting of less than 30, I will opt for the DD design. DD coils are made to "offset" the effects of mineralization and will provide more stability, and generally more depth. JMHO HH Randy
