White’s Electronics Spectra VX3 - Manual (Page 56)

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Spectra VX 3 User’s Guide
Icons
Icons are simply a pictorial representative possibility of the
VDI number. Because many different targets can overlap in
their VDI numbers, sometimes two icons are presented as possi-
bilities. For example, pull tabs and gold rings often share VDI
ranges. As you learn VX
3 , you should find yourself paying less
attention to the icons and more to the VDI number and the
SpectraGraph bars.
Depth
The depth readout in normal search mode is only an esti-
mate. With any detector, depth is calibrated for particular tar-
gets, usually certain coins, and many other targets may show a
large error. For example, ring targets can be deeper than their
displayed depth, and shallow stainless steel may display a
deeper reading.
Furthermore, the depth displayed in search mode is a “live”
depth reading where the signal has passed through several
stages of filters. Live depth can vary with sweep speed, typi-
cally reading deeper as you sweep slower. Pinpoint depth is
based on a static signal and is usually more accurate. Use the
live depth reading with a degree of skepticism, and the pinpoint
depth as more realistic.
SpectraGraph
The SpectraGraph ® display is a progression of White’s Sig-
naGraph ® which was used in XLT and DFX. Besides the addi-
tion of color, SpectraGraph plots the response of each frequency
separately, so you can see individual variations in the VDI
responses, amplitudes, and decays. The highest frequency is
always on top. Obviously, in a single-frequency mode only one
frequency is plotted.
SpectraGraph plots target signal strength versus VDI. Note
that the VDI axis is not linear; the negative half (-95 to 0) is
compressed compared to the positive half (0 to +95). This is