SignaGraph: Say what?

So I had a short time to hunt last night and strapped on the Super 12 and headed for the city park. In a very hard hit location I get a very confusing signal that was all over the VDI as well as the tones. Impossible to determine what it could be I fell back to the Spectrum series detectors failsafe. The SignaGraph. I set it for accumulate and a pattern begin to show. I made the call and did my recovery to find a small pocket spill of 2 wheats(1919 and 1935), a Wichita transportation token and a 1941 nickle and a small rusted piece of pipe. It was then I realized that a lot of Spectrum users have this very valuable tool, but may not know how to use it.

The SignaGraph is my failsafe when all other input fails. For those who aren't familiar with this feature, it is a bar graph on the lower portion of the display that takes the signal and builds a bar graph that can be used to help identify a target. It is akin to the Ferrous input on the minelabs with a plus. The plus is since it is a bar graph, and not numbers that refresh on each swing, each swing over the target builds a graph of the numbers from each swing. For example, if 5 swings were to give 5 different numbers, it would build a graph showing all the numbers received instead of the numbers changing each time. This makes building an average much easier than trying to remember the numbers on each swing.

If the target(s) is of ferrous(iron) content, each swing will begin to build up the graph in the ferrous range. If a good target is within the swing of a bad target, you will see it on the graph. Just as I did last night. The graph also can really help distinguish that gold target from the foil and tabs. I've taken some pictures to help explain how the SignaGraph works.

There are 3 adjustments for the SignaGraph. Graph Averaging, which takes the signals and builds you an average of all the signals received. Graph Accumulate which takes the signals and shows them all so you can spot the possible good in with the bad. The Fade Rate adjusts how long the graph is displayed before it fades or refreshes. Opps hit post too soon. The hight of the bars indicate the targets signal strength or depth.

Here is a picture showing a typical graph in the field. The scattered graph indicates junk but the build at the far right indicates a possible good target along with the junk. Bars to the left of center indicate a ferrous target while bars to the right of center indicate conductive targets.



Here is a typical graph of a 14k gold ring. Note the single bar that corresponds with the VDI number of 14. Also note that the Icons at the top right show possible foil or ring. A good indicator it is not foil or a tab. By the hight of the bar the target would be roughly 3" deep.



This graph show a possible nickle/ring at roughly 5-6" deep. Notice as the target gets deeper you start to see more smearing of the bar graph, but you can still see the build indicates a good low conductive target even though the VDI is different on each swing and the tones are all over the scale.



Here is another typical graph of a good target(penny) with trash by it. The VDI jumps from -32 to +79 and the sound is hard to make a call from, but the build up of the bars on the far right(good area) outweigh the bars to the left indicating a probable good target at roughly 4-5".



Here shows a more than likely piece of foil. The pattern is smeared but the build up corresponds with the VDI number of 3, and the Icons matches as well.



Here is a graph showing a good clean dime signal at about 5". No smearing and even at 5" the bars are prominent in the dime range of the graph. Look at the graph as the center being 0. Anything to the left counts down as minus number to -95, and anything to the right of center(0) counts up to +95.