RHOTHETA User Manual RT-800
Page 42 of 192
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. 6.4.2.1).
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 Fig. 39 in the chapter 6.2.4.
For “SAR Scan”, “Fast Channel Scan” and “Monitoring” the last result is shown in the digital
bearing display (s. Fig. 17, 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 North/0° mark of the antenna (fixed installation) respectively
vessel’s/vehicle’s heading at the time of the bearing (mobile installation). A change of heading
in the meantime must be considered.
6.1.5 Function Clear
The function “Clr” (s. Fig. 5, position 8) 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. 6.1.2.1).
If the “GPS Arrow” was exported to the “Bearing” page (s. 6.3.5), keep the “Clr” hotkey
pressed for a few seconds in order to remove the GPS arrow indication.
6.1.6 Function Autoset Squelch
In normal bearing mode (no scan active) the hotkey “Autoset SQL / Squelch / Automatic /
Manual” hotkey is designated as “Autoset SQL” (s. Fig. 5, position 9). 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. 6.4.3.13). A manual readjustment might be necessary (s.
chapter 6.5.3).
1
Typical case is a quick pass on the transmitter, which is in the near field of the DF-antenna.
