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
SQUELCH/OPTIONAL SELCAL
Squelch is set by rotating the larger outer concentric knob (lower left)
clockwise until background noise can be heard and then turning it
counterclockwise until background noise is eliminated or just barely
audible.
CAUTION: It is important to know that squelch operation in HF is not
as predictable as in conventional VHF communications. It is not
unusual for conditions to make it necessary to leave the
squelch knob fully clockwise to maintain satisfactory reception.
Otherwise the signal may fade below the threshold you have set on
the squelch, and you may miss an important message from a ground
station. This is unlike VHF receiver squelch where you are normally
dealing with a strong, non-fading signal. For this reason SELCAL or
ALE may be a desirable option.
MODE SELECTION
USB MODE A3J MODE
Operation
3-63
KHF 950/990 Pilots Guide
Rev. 0
Dec/96
1
S
T
O
HF
OFF
TELAM
USB
LSB
A3J
A3A
VOL
SQ
345.6
19 - 12
CH
M
H
Z
K
H
Z
Figure 3-76 Squelch/Optional SELCAL
1
S
T
O
HF
OFF
TELAM
USB
LSB
A3J
A3A
VOL
SQ
417
19 12
CH
M
H
Z
K
H
Z
1
S
T
O
HF
OFF
TELAM
USB
LSB
A3J
A3A
VOL
SQ
345.6
19 - 12
CH
M
H
Z
K
H
Z
Figure 3-77 Mode Selection