B&G HS2000 - Manual (Page 82)

HS 2000 User Manual
Part 6 - Diagnostic Data
HB-0846-03
6-9
6.2.3 Consistently Shows Shallow Depth
Symptom: Display consistently shows a shallow depth between 0
and about 1.5m.
Possible causes:
(a) Faulty transducer. The transducer rings for too long
after the transmit pulse is sent and the ringing is
interpreted as a shallow return by the Depth Sounder. On
a deep keeled boat it may be possible to overcome this
problem by increasing the minimum depth to just less
than the draft of the yacht. The minimum depth is
adjusted by changing CAL VAL1 on NOISE.
PARAMTR ? NOISE, CALBRATE ? CAL VAL1 (MIN DPTH M)
The default setting for minimum depth is 0.7 metres.
(b) Keel echoes. If the transducer has been installed too
close to a deep keel, it is possible that consistent echoes
from the keel are being received. The transducer should
be re-sited further away from the keel. If this is not
possible, 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 transducer main beam and may be rectified 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.
6.2.4 Random Deep Depths
Symptom: Display shows random deep depths.
Possible causes:
(a) Electrical noise. The Depth Sounder incorporates
circuits and software to reduce the susceptibility to
electrical noise, however, this can still present problems if
not installed carefully, or other equipment is incorrectly
suppressed. The Depth Sounder measures the ambient
noise which can be displayed by viewing the PARAMTR
Menu. When the boat is stationary, electrical equipment
should be switched ON and OFF, in turn, while viewing
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, in all likelihood this