14 - English
SeekTech
®
ST-33Q
Ground both ends of the utility for the best signal
induction�
The ST‑33Q will also default to 50 percent power level
to conserve battery power while in Inductive Mode� If
higher power is required for a clear signal, use the Up
and Down Arrow Keys
and select either 25 percent,
50 percent, or 100 percent� In High Output Mode, a
power of 200 percent can also be selected� Using
a power level of 100 percent or greater will drain the
batteries rapidly� The power‑setting boxes will blink if set
at 100 mA or higher to indicate the higher rate of battery
consumption (
See Figure 19).
Figure 19 – High Power Level Warning
Self‑Tuning Transmitter
In Inductive Mode, the ST‑33Q self‑tunes by modifying
its own circuit to resonant at a frequency that matches
the frequency selected by the operator�
In rare situations, if using Induction Mode near a mass of
metal or next to a transformer for example, the ST‑33Q may
not be able to tune to a desired frequency� The ST‑33Q will
attempt to tune to a desired frequency for up to 6 seconds�
If the ST‑33Q cannot tune to a desired frequency after
6 seconds, the ST‑33Q will suspend output, display a
warning, and emit a low beep (
See Figure 20)
�
Figure 20 – Self‑Tuning Warning
If the ST‑33Q cannot tune to a desired frequency
perform one of the following:
1� Press the Select Key to attempt to retune at the
current frequency�
2� Press the Inductive Mode Key to return to Direct
Connect Mode�
3� Move the ST‑33Q to a different location to perform
the locate�
4� Press the Frequency Key and select a different
frequency to try in Inductive Mode�
Air‑Coupling
In Inductive Mode, the ST‑33Q will generate a field
through the air around it; including the ground underneath�
If within air‑coupling range of the ST‑33Q, the receiver
will measure this field instead of the target conductor�
Air‑coupling may distort readings and misconstrue the
location of the target conductor�
Air‑coupling can occur over a wide range; greater than
70 ft [20 m] if the induced utility is deep and poorly
grounded� Very weak induction and deep utilities will
result in greater air‑coupling distances� Always confirm
the detection of utilities and the readings of depth
measurements�
Air‑coupling does not depend on the output power of
the transmitter and cannot be reduced by turning down
the power� Air‑coupling only depends on the ratio of the
field from the transmitter compared to the induced field
in the target utility�
Note that air‑coupling can vary continuously� Be aware
of the difference between the transmitter’s field and
the induced field of the utility being traced� While both
will have the same frequency, the transmitter’s field is
limited to the region around the transmitter itself� Be
sure to look overhead for power lines that could also
confuse the locate�
Testing for Air‑Coupling
To test for air‑coupling, tilt the locator at a 45 degree angle
towards the ST‑33Q and ensure the lower antenna of the
locator touches the ground� Afterwards, tilt the locator
45 degrees away from the ST‑33Q and observe the
depth reading� If the depth reading changes significantly,
air‑coupling may be occurring (
See Figure 21)
�
Figure 21 – Testing for Air‑Coupling
Alternatively, test for air‑coupling by standing 20 ft [6 m]
away from the ST‑33Q� With the lower antenna on the
ground, take note of the indicated depth measurement
on the locator� Raise the locator vertically 18 in [45
cm] and observe the change in the depth indication� If
the locator only reads the conductor, the depth should
increase accordingly� If the locator is air‑coupling, the
depth indication will not change by 18 in [45 cm], but will