Apr/2006; 3) Channel Mode; 4) Direct Frequency Mode; 5) Data Mode - Honeywell KHF 1050 System Installation Manual

3.B.(3) Channel Mode
When operating in the channel mode the KHF 1050 HF system can operate as
a simplex or semi-duplex communication system. Transmit and receive
frequencies are selected by selecting a pre-programmed channel.
The KHF 1050 supports three types of channel mode operation:
• User programmable channels (up to 99 channels, depending on the
controller used)
• 6 Emergency channels
• 246 ITU (Maritime Service High Seas Operator) channels
The emission mode is also part of the stored channel information.
3.B.(4) Direct Frequency Mode
When operating in the direct frequency mode the KHF 1050 HF system
operates as a basic communications system. Transmit and receive frequency
is determined by the selected frequency, which is entered directly on the control
unit.
3.B.(5) Data Mode
When the KRX 1053 Receiver/Exciter is operating in the DATA mode, interface
with data modems or secure voice systems is enabled. The external modem
inputs and external modem outputs are available to bypass squelch and
compression functions in the KRX 1053. These levels are controlled by field
adjustments.
A 4 dB variation with reference to 1 KHz is possible in the audio response when
operating in the data mode.
Audio modulation from the modem is applied to the EXTERNAL MODEM
AUDIO INPUT. When the DATA KEYLINE is grounded, the transmitter
modulation is derived from the DATA AUDIO INPUT rather than from the
microphone.
3.B.(6) SELCAL Mode
NOTE: SELCAL mode requires a SELCAL decoder, not supplied.
SELCAL (SELective CALling) may be used to relieve background noises during
flight. The volume may be turned down completely while the system maintains
a watch for a SELCAL coded audio signal.
Revison 2
N
KHF 1050 SYSTEM INSTALLATION MANUAL
23-10-09
Page 28

Apr/2006