B&G H2000 Pilot *DISCONTINUED* - Manual (Page 215)

HB-0845-06 215
b. Keel echoes. If the transducer has been installed
too close to the keel it is possible to get consistent
echoes from the keel. The transducer should be re-
located further away from the keel. If this is
impossible then increasing the minimum depth to
just below the keel can solve the problem but may
result in poor performance when the bottom is
shaded by the keel. Marginal cases are sometimes
caused by side lobes from the main beam from the
transducer and may be cured by rotating the
transducer in the housing.
c. Following or crossing the path of another vessel
which has left an aerated layer in the water.
6.3.4 Random Deep Depths
Symptom: Display shows random deep depths.
Possible Causes:
a. Electrical noise. The depth sounder contains
circuits and software to reduce its susceptibility to
electrical noise, however this can still be a
problem if not installed carefully or other
equipment is not correctly suppressed. The depth
sounder measures the ambient noise and this can
be found for display by looking under the
PARAMTR Menu. When the boat is stationary
electrical equipment should be switched ON and
OFF in turn while looking at the depth and noise
displays to try and determine the source of the
problem.
b. Acoustic Interference. Other depth sounders and
sonar can cause problems. However this is
generally only when very close to other boats for
example when moored alongside in a crowded
marina. Also acoustic noise can be generated by
water flow past the transducer and various bits of
mechanical machinery.