This is an excerpt from the Tejon tips and tricks article I mentioned earlier. I don't know if other Tesoro detectors respond this way, you guys let me know. Hope this helps.
BASIC BEEP ANALYSES
The seemingly lowly "beep" is actually a rich storehouse of information on the
Tejon. It is composed of two principal components---the on/off transients
(i.e., the "b" and the "p") and the longer duration "ee." Both of these
components aid in lDing and estimating target depth with the "b" and "p"
being somewhat more useful in IDing a target and the "ee" taking the lead in
depth estimates.
NOTE: The discrimination circuitry in the Tejon is useful down to about 11"-
12". Beyond that depth, you must use the all-metal mode and are mostly
limited to "profiling" (although depth estimates can be made).
THE 'b' AND "p" ANALYSIS---In the all-metal mode, the information in these
components is minimal and, as noted, limited mostly to profiling and depth
estimates. In the discrimination mode, however, they really come alive and
there are some basic rules of thumb to go by...
1. On targets ABOVE the discrimination level you have set, the rise/decay
time of the "b"/"p" transients will be relatively long in duration. That is, they
will have a "smooth" sound. Shallower targets sound "full" and "smooth,"
deeper targets still sound smooth but can take on a "squishy," "less full"
character.
2. As your target's conductivity APPROACHES the discrimination setting, the
rise/decay time shortens and the "b" and "p" begin to sound more "abrupt."
It may still be a "good" target but its conductivity will be closer to the cut-off
point. For example, if you have your discrimination set to just accept zinc
pennies, the zincs will sound more "abrupt" than higher conductivity coins.
3. Targets EQUAL TO the discrimination setting will take on a "crackle"
character.
4. Targets BELOW the discrimination setting will either disappear or possibly
sound off as "pips" or "chatter."
5. When X'ing from different directions, listen for the "worst case" scenario.
That is, if you get a smooth response in one direction and a more abrupt "b"
or "p" in another direction, consider the more abrupt transient as the most
meaningful. (EXCEPTION: In masking situations you have to proceed to
analyzing the "ee" in beep; see below.)
As an example, steel crown caps with their convoluted rims will often sound
smooth in one sweep direction but you can almost always hear the "ra-ta-tatats"
of the edge in another sweep direction.
So, in summary, the "worst smoothness" of the "b" and "p" in any sweep
direction gives you the best indication of where the target falls in relation to
your discrimination setting.
THE "ee" ANALYSIS---The "ee" in the "beep" is most obviously useful in
estimating the size and depth of an object. But its value extends beyond that.
Similar to the "b" and "p," listening carefully to the "ee" can provide useful ID
info. Again, some rules of thumb...
1. Targets well ABOVE your discrimination setting will give a "full tonality
'ee"' (that will vary in duration depending on sweep speed and target size).
2. As a target APPROACHES the discrimination setting, the "ee" will sound
"thinner" and, perhaps, somewhat weaker.
3. Targets EQUAL TO the discrimination setting tend to given intermittent
"eg" sounds.
4. Targets BELOW the discrimination setting WILL GENERALLY LOSE
TONALITY. This latter quality can be useful in masking situations.
Masking---When a discriminated-out target is near a desired target,
sometimes a detector will fail to "see" the desired target. Many times, this
situation will reveal itself as an "ifft/" target, with an uncertain size and
different signals depending on sweep direction and/or speed. If shortening
your sweep fails to differentiate the possible two (or more) targets, listen fur
any sign of tonality. If the target(s) are completely below your discrimination
setting, there won't (in most cases) be any sign of tonality in the "ee." On the
other hand, even an occasional "ee' sound means you should probably dig it.
Exceptions: Sometimes large or problematical items (e.9., rusted iron, fruit
juice seals, washers, etc.) will power past the discrimination setting and give
a signal with tonality...I've yet to come up with a procedure to avoid these
types of mis-IDs. Also, in theory (but rarely in practice in my experience), the
conductivities of two "bad" targets can "sum" or "average" to give an
erroneous conductivity reading that's above your discrimination setting but
I've never encountered this with the Tejon (but I have with my ID machines).
Coins on edge.--Sometimes when you are sweeping a small target that you've
guessed is "good," you'll notice that the fullness (and duration) of the "ee"
may be somewhat less in one sweep direction than in another. In my
experience, a high percentage of the time this is a coin on edge.
Coin denomination---At a constant sweep speed, and with practice, you can
learn to tell with somewhat surprising accuracy, the difference between a
dime and a quarter by listening to the duration of the "ee" (and, therefore,
the size of the target), I can also usually (but not always) tell the difference
between a copper penny and a quarter, but not between a copper penny and
a dime. Zincs and nickels are handled with the dual discrimination of the
Tejon.
So, in summary, besides size and depth estimates, analysis of the "ee"
sounds can tell you how close to your discrimination cut-off point a target is
and can aid in the ID process.
This is already pretty long so I'll save depth estimates, dual discrimination,
etc. until next time.
In closing, let me state that to use the preceding tips optimally, you need a
good set of ears and a good set of headphones. You also will likely need
practice TRYING TO HEAR the cues. If you presently have "untrained ears,"
you may or may not be able to hear some of the subtle cues that the Tejon
provides.
Much like learning a foreign language (which initially sounds like gibberish), hearing these cues
takes practice before things start differentiating themselves and the "light
goes on".