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Operating Manual
Bearing System RT 300
which received signals will not be processed. Usually the sqelch threshold is adjusted as
close as possible above the noise level. In that case the bearing system will work only, if a
signal is received. As long as no signal is received, the speaker is remaining mute.
Important: The squelch level is to be kept as low as possible in order not to suppress weak
signals.
3.2.4.2 Adjusting the Squelch
Pointer squelch level
The squelch level is to be adjusted,
receiving level
when receiving no signal.
bar graph
- pressing key 14 <Squelch> , the
digital level display
„Adjust Squelch“ -window will
digital value of squelch
appear.
level
- Key 8 <> is starting the
Fig. 19
automatic squelch setting procedure. For a duration of
about 3secs the signal level is measured, and then the squelch level will be set ca. 3 %
above the peak value of the measuring period. After that the „Adjust Squelch“- window
will reappear.
- Using keys 5 <+> resp. 10< -> the squelch level can be adjusted manually.
- The pointer on the top of the graphic display and the digital display are indicating the
present level of the squelch threshold.
- Pressing key 3 <> disables the squelch function (level will be set to 0%).
- Key 6 <Ok> confirms the input and the device will return into the bearing mode.
- Key 9 <Esc> will reject the selection and the device will return into the bearing mode.
- If no confirmation, using key 6 <OK> is done within 25 secs after the last input, the
device will return into the bearing mode with the previous adjustment.
The squelch level for the airband and for the maritime band are adjusted and saved
separately. On different frequencies within the range of one band the noise level may be
varying significantly. Coastal areas with industries may show higher noise levels than in
offshore areas. This makes it important, to periodically check the squelch adjustment, and, if
required, to readjust the squelch level in order to acquire highest sensitivity of the bearing
system.
Remark:
While bearing emergency transmitters, which are transmitting often very weak signals, it
may be useful to deactivate the squelch function in order to obtain highest sensitivity of the
bearing system. In this case it is important to check continouosly if the transmitter is beared
and not an interfering signal. This can by verified by changing the heading, causing a
change of the relative bearing value. If required, actuate the "Clear"-function (see 3.2.10)
3.2.5 Volume Key 5 <Vol.+> and 10 <Vol –>
Pressing key 5 <Vol +> resp. key 10 <Vol -> in the
bearing mode, the window „Adjust Volume“ appears.
- Further actuating of key 5 increases continuously
- the volume, key 10 decreases the volume.
Bar graph and digital display are indicating the
selected percentage (see Abb. 20) of the maximal
volume.
Issue: 2013/03/04 [Rev 1.03.a]
Page 21 of 72
Abb. 20
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