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
IIIIIIIII * Interval type ActvLim, ScnRate, Sound, CallTime
XX * Interval
UUU unit of measure
* Cursorable fields
Activity Limit Time-Out Period (ActvLim)
ActvLm stands for activity limit. The activity limit is the amount of
inactive time, in minutes, allowed while linked before a radio automat-
ically hangs-up and returns to scan. The inactive timer runs whenev-
er the radio is linked and in receive. The timer is reset each time the
microphone key button is released. When the inactive timer reaches
the time limit set in ActivLim the radio will hang-up causing both the
calling and called radios to return to scan. The activity limit which is
specified in minutes ranges from 1 to 60 minutes, it can be disabled
by setting the interval to “0 OFF”.
Scan Rate (ScnRate)
The scan rate, specified in hertz (Hz), is the rate at which the radio
scans through the channels on the scan list. The scan rate can be
set to either two channels per second (2 Hz) or five channels per sec-
ond (5 Hz). Five channels per second is the default scan rate.
Automatic Sounding Interval (Sound)
When sounding is enabled this time interval is the amount of time
between automatic sounds. Sounding is a one direction, non-inter-
active broadcast of a radios self address. Other radios receive the
sound and use it to measure the quality of the received signal. The
sound interval is specified in minutes, ranges from 1 to 240 (4 hours).
CallTime (CallTime)
This is the amount of time that the ‘scanning call’ portion of the call
wave-form is transmitted. The scanning call can be thought of as the
preamble to the call and is used to get the attention of the listening
radios. Since a radio that is being called may be anywhere in the
scan list cycle, the call time must exceed the time it takes for that
radio go completely through its scan list.
The CallTime is specified in seconds and is set for the longest scan
Operation
3-33
KHF 950/990 Pilots Guide
Rev. 0
Dec/96