Yaesu FT-991A, Руководство по эксплуатации

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Page 40 FT- 991 Operating Manual
Convenience Features
AMS
(
Automatic Mode Select
)
Operation
The transceiver has the AMS (Automatic Mode Select) function which enables the transceiver to automatically select
the most appropriate option out of the three communication modes according to the received signal while operating in
C4FM mode.
Besides C4FM digital signals, analog signals (FM)
are also identified in order to automatically match the communica -
tion mode of the partner station.
Note:
The AMS function recognizes the three modes listed in the following table. Other communication modes cannot be rec-
ognized.
Operating Mode Display Explanation of Modes
V/D mode
(simultaneous voice and data
communication mode)
DN
When AMS is “ON”: Red
When AMS is “OFF”: Light blue
As the audio signal error is detected and repaired at the
same time as the transmission of the digital audio signal,
it becomes more difficult for conversations to be cut off. A
basic digital mode of C4FM FDMA.
Voice FR mode
(Voice full-rate mode)
VW
When AMS is “ON”: Red
When AMS is “OFF”: Light blue
Digital voice data is transmitted using the entire 12.5 kHz
bandwidth. High quality voice communication is possible.
Analog FM mode AN
Only when AMS is “ON”: Lights red
Analog communication mode using the FM mode.
This mode is effective for communication when the signal
strength is so weak that the voice is cut off midway in the
digital mode.
1. Press the MODE button, and then touch the corre-
sponding key on the LCD to select the C4FM operat-
ing mode. The “ C4FM ” icon appears in the display.
2. Touch [ AMS
] on the LCD. The AMS function will
switched to “ON” and the communication mode will
be switched to match the received signal.
Note:
MODE Button
In the V/D mode (“ DN ” displayed), the position infor-
mation is included in the transmitted signal during the
conversation, but in the Voice FR mode (“ VW ” dis-
played), the position information is not included.