Book Excerpt: “Signal Acquisition and Examination”


Signal Acquisition and Examination

While we are on the subject of acquiring signals it’s worth mentioning that setting your detector to acquire targets to its full potential is a skill in itself. While I don’t want to go into simple basics here I will make the one point that a huge number of new hunters just have too much faith in their machines to punch through the ground –at any Sensitivity setting. Over time we learn that any detector has limitations and the best way to see what a machine will do and avoid the frustration of digging false signals and indistinguishable junk is to start off with low settings. This is part of letting the conditions dictate—the subject of this book.

Another skill that I’ve tried to emphasize the importance of is signal examination. Conducting detailed and systematic examination of your signals saves frustration and conserves energy. When you learn to use both discriminate and all-metal modes to look for sets of target characteristics your accuracy and overall hunt speed improves. These skills should include:

-the ability to tell small surface junk signals from deep, solid ones (see consistency and “turning” a response, below).

-understanding “carry”–how iron signals differ from non-ferrous responses in the strength (and shape) of the field that they emit. This is something that bench testing will help with.

-the ability to use your detector’s all metal mode to distinguish a good, narrow noon-ferrous signal from a wide, drawn out target that contains iron or steel.

This should be combined with a general understanding of how objects that contain iron “blend” electromagnetically with the ground. I mention this because it effects the way an object will pinpoint. A non ferrous target will centre in the same spot as you acquired it in discriminate mode, whereas an ion object will appear to move as the machine responds to the changing field.

When you understand this principle. It’s possible to begin to gain additional information about targets by the sounds and effects produced by this interaction between ground and target . The more distinct it is—that is to say the cleaner and sharper the transition—the better the signal.

A few more related signal testing methods include:

Turning a signal”

This is an old-timers technique that tests the consistency of the signals relation to the surrounding ground. Step to one side of a target and check how it responds on the cross-sweep. If it breaks up or appears to move—its likely iron. If it stays consistent from multiple angles—it’s a good target. Combine this cross-sweep method with sweep speeds and lengths to learn more about your response’s size, shape and depth. This is especially important with some of these newer high-gain detectors that are just super sensitive. (Examples include the Minelab CTX 3030, the Macro Racer 2 and the Nokta Impact). As well though because these modern detectors process signals with a high level of efficiency these kinds of signal tests will be much more effective—in conjunction with the machine’s built in bias towards clean, non-ferrous metals.

I mention this because of the numerous posts I see on Internet Forums from hunters who have purchased expensive machines and can find only junk because they lack these simple basics. It’s as if they are so transfixed by the “bells and whistles” on these newer detectors they forget the need for any operator skill whatsoever.

At the same time, these methods for narrowing down the identity of a response should be tempered with open mindedness. No discrimination circuit is perfect, and things like target inclination, masking and changes in the ground’s composition can cause objects in the ground to respond in strange ways. As well, there are a lot of small gold targets at the beach that just won’t give much of a signal. Chains, bracelets, earrings, flat pendants—all of these types of targets can give an inconsistent response. However, the same principles still do apply. Gold will always be a signal that has some distinct features as compared to iron or tinfoil. The greater the range of signals characteristics you are prepared to examine—the better will be your chances of recognizing these quality responses.

This is especially true in situations where its necessary to separate gold or silver from other objects that are very similar.

Modern, sophisticated detectors such as the CTX 3030 and Nokta Impact still require the operator to have solid basic skills to accurately harness their high gain sensitivity.

From: “Water Hunting: Secrets of the Pros” Volume II” by Clive James Clynick