Technical information
Table Of Contents
- TITLE PAGE
- TABLE OF CONTENTS
- INTRODUCTION
- SECTION I
- CHARACTERISTICS OF HF SSB
- ACRONYMS AND DEFINITIONS
- REFERENCES
- HF SSB COMMUNICATIONS
- FREQUENCY
- SKYWAVE PROPAGATION - WHICH FREQUENCY TO
- WHY SINGLE SIDEBAND IS IMPORTANT IN HF
- AMPLITUDE MODULATION (AM)
- SINGLE SIDEBAND OPERATION
- SINGLE SIDEBAND (SSB)
- SUPPRESSED CARRIER VS. REDUCED CARRIER
- SIMPLEX AND SEMI-DUPLEX OPERATION
- AUTOMATIC LINK ESTABLISHMENT (ALE)
- FUNCTIONS OF HF RADIO AUTOMATION
- HOW ALE ASSURES THAT THE BEST COMMUNICA-TIONS
- CHARACTERISTICS OF HF SSB
- SECTION II
- SECTION III
- SECTION IV
- SECTION V
- SECTION VI
- SECTION VII
- ITU MARITIME RADIOTELEPHONE STATIONS
- DESCRIPTION OF SERVICES
- AT&T HIGH SEAS RADIOTELEPHONE SERVICE
- AT & T COAST STATION COVERAGE MAP
- COAST STATION COVERAGE & INFORMATION
- AIRCRAFT REGISTRATION
- OPERATING PROCEDURES FOR USING THE HIGH SEAS RADIOTELEPHONE NETWORK
- AT&T HIGH SEAS COAST STATIONS
- MOBILE MARINE RADIO, INC.
- WORLDWIDE LISTING OF PUBLIC CORRESPONDENCE STATIONS
- MARITIME RADIOTELEPHONE CHANNEL DESIGNATIONS
- SECTION VIII
- SECTION IX
- SECTION X
- SECTION XI
- SECTION XII
- SECTION XIII
CAUTION: When performing a ` radio check on the ground,
make certain that all personnel are clear of the HF antenna
before transmitting. SERIOUS RF BURNS CAN RESULT FROM
DIRECT CONTACT WITH THE ANTENNA OR ANTENNA TERMI-
NAL WHEN THE SYSTEM IS TRANSMITTING.
ANTENNA TUNING
When using a KCU 1051 control display unit, the antenna coupler
tune information is stored in non-volatile memory. This means that
retunes are required only when new frequencies are entered into the
channel non-volatile memory. For semi-duplex channels both the
receive and transmit frequency is tuned to provide optimum perfor-
mance.
When using a KCU 951 or a KFS 594 the antenna coupler retunes
the antenna under the following conditions:
1. When the system is first turned on (and warmed up) and the mic
key is pressed.
2. When a new channel or frequency is selected and the mic key is
pressed. Always initiate a tuning sequence after selecting a new fre-
quency or channel. A tuned antenna improves receiver performance.
3. When an existing channel or frequency is being used while the
unit senses an improper match and the mic key is pressed.
The antenna coupler is always utilized when transmitting (regardless
of mode) and while receiving in the simplex mode (after mic key is
pressed for tuning). The antenna coupler is bypassed during receive
when operating in semi-duplex or receive-only channelized operation.
The system is then functioning as a receiver connected directly to the
HF antenna.
FAULT INDICATION
When using a KCU 1051, if the system detects a fault, a flashing “M”
appears in the upper right corner of the display, and a fault message
is displayed on the second line. The fault message reads “High
VSWR” if there is an antenna problem, otherwise it reads “Fault see
MSG pg”. If connected, the Remote light also annunciates. The fault
messages can be viewed on the message page by pressing the
MSG key. If a High VSWR fault occurs, key the microphone to cause
the automatic antenna coupler to begin a new tuning cycle to clear
the fault.
Operation
3-2
KHF 950/990 Pilots Guide
Rev. 0
Dec/96