Rhotheta RT-500-M, Руководство пользователя

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RT-500-M
RHOTHETA Page 38 of 168 User Manual
Depending on the availability of compass or GPS data, also other information can be displayed in the
numeric bearing indication window (s. Figure 23, field A).
The last valid bearing data will be shown for 2 seconds (by default) after pressing the “Repeat” hotkey.
This hold time can be changed on the “Setup” page (“Bearing Indication Hold Time”, s. 7.4.2.1).
The repeat function during a scan is displayed differently depending on the current scan procedure.
For all scan procedures, except “SAR Scan”, “Fast Channel Scan” and “Monitoring”, the repeat
function shows the information about the last valid bearing in the left upper corner of the DCU display
e.g. as it is shown in the Figure 45 in the chapter 7.2.4.
For “SAR Scan”, “Fast Channel Scan” and “Monitoring” the last result is shown in the digital bearing
display (s. Figure 23, digital bearing display indication with bearing arrow) and the corresponding
frequency is marked with a gray circle, e.g.:
.
If a new signal is detected, the repeat indication interrupts and adopts the new bearing value.
If an external compass is activated (“true” / “magnetic” bearing), a change in the heading of the ship is
automatically considered for the bearing.
Note
If no external compass is activated (“relative” bearing), the indicated bearing value corresponds to the
vessels heading at the time of the bearing. A change of heading in the meantime must be considered.
7.1.5 Function Clear
The function “Clr” (s. position 8, Figure 11) clears the internal bearing value averaging memory.
The averaging memory improves the bearing accuracy and provides a useful bearing indication even
with poorly received signals (e.g. distant transmitter, receiving gaps).
The averaging procedure can cause a dragged error, which might affect the bearing value, if the
heading changes too fast
1
. In this case, the indicated bearing value will slightly lag behind the actual
bearing value.
Pressing the hotkey “Clr” after a distinct change of heading will correct the displayed bearing value
immediately.
If an alarm was activated, this hotkey is used to mute the acoustic alarm (s. 7.1.2.1).
If the “GPS Arrow” was exported to the “Bearing” page (s. 7.3.5), keep the “Clr” hotkey pressed for a
few seconds in order to remove the GPS arrow indication.
7.1.6 Function Autoset Squelch
In normal bearing mode (no scan active) the hotkey “Autoset SQL / Squelch / Automatic / Manual”
hotkey is designated as “Autoset SQL” (s. position 9, Figure 11). Pressing this hotkey will
automatically set the squelch level above the noise level by 6 dB (this is a default value and can be
modified in “Setup”, s. 7.4.3.12). A manual readjustment might be necessary (s. chapter 7.5.3).
When bearing a Cospas-Sarsat frequency this hotkey is designated as “Manual”/ “Automatic”, which
allows switching between these squelch adjustment possibilities. For further information please refer
to chapter 7.5.3.
1
Typical case is a quick pass on the transmitter, which is in the near field of the DF-antenna.