Furuno Navtex NX-700-A, Service Manual

Page: 102 / 142

7.2 Rcv Monitor
7-10
7.2 Rcv Monitor
This section describes information on monitoring of received signals.
To monitor a received signal on audio frequency,
Select “Int’l (518 kHz)” of “Local (490 kHz or 4209.5 kHz)” in “[MENU] ->
System -> Signal Monitor”.
To output monitor sounds, internally created audio frequency is outputted if the
received signal component has frequency component above 1700 Hz. If frequency is
below 1700 Hz, audio frequency is not outputted.
Related information:
To switch to local frequency, select “[MENU] -> NAVTEX -> Local Channel”.
7.2.1 [MENU] -> Service -> Rcv monitor
A message being received can be displayed in real time to monitor the receiving
condition. For instance, even when icons
I
and
L1
(
L2
) to show the “receiving”
status are blinking, reception is stopped halfway, it may be caused due to the condition
of radio-wave propagation, failure of the Receiver unit, noise jamming or etc.
A message is displayed as received.
Reference:
The conditions for displaying (printing) a received message is;
- it is synchronized to the synchronizing signal broadcasted before ZCZC,
- ZCZC and message ID can be received correctly,
- the reception error rate is 33 % or less, and
- NNNN as the ending signal can be received.
System
Warn Msg Alm Off
Signal Monitor Int’l
Key Beep ON
Time Offset 00:00
Units nm. kt
Printer None
Off
Int’l
Local
Phasing signal
>> 10s
ZCZC
One
space
B1B2B3B4
CR
+ LF
Message NNNN