SEA 235, Руководство оператора

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GLOSSARY
97
DEFINITIONS
This manual assumes basic HF SSB radiotelephone knowledge. Below are
definitions of acronyms used in the operating instructions.
AF : A udio F requency
AGC : Used in the receiver of a radio, the
A
utomatic
G
ain
C
ontrol adjusts the
radio circuitry to compensate for large and small signals.
ALC : A utomatic L evel C ontrol keeps the transmit power from overshooting.
AME : Only used for 2182.0 KHz, A mplitude M odulation E quivalent allows a
single side band radio to be intelligently heard on an older AM marine radio.
Bin / Channel : A number assigned to a pair (transmit / receive) of frequencies
stored in the radio memory. While both are pre programmed, for the purpose of
this manual, ‘
Channels ’ are permanent in memory and can not be changed by
the operator. ‘ Bins ’ are channels that can be programmed by the operator.
Carrier : A reference frequency for a channel. Normally 0 Watts for SSB
transmissions. AME uses a 40 Watt carrier and R3J uses a 5 Watt carrier.
DSC :
D
igital
S
elective
C
alling is a more advanced NECODE system.
DUPLEX : A channel using different transmit and receive frequencies.
ITU : I nternational T elecommunications U nion.
KHz : K ilo (thousand) H ertz. Commonly used when referring to a single HF
frequency such as 2182.0 KHz.
LSB : The opposite of USB is L ower S ide B and and not allowed for marine use.
MHz : M ega (million) H ert z . Typically used when referring to a band of
frequencies such as ‘4 MHz band’.
NECODE : A signaling device for calling a specific station also using NECODE.
PTT : P ush T o T alk refers to the microphone button.
R.I.T. : R eceiver I ncremental T uning allows changing the receiver frequency.
SQUELCH : A circuit that mutes the speaker when no signal is present.
SSB : S ingle S ide B and. The carrier is removed along with one sideband.
TELEX : Data communications that requires a special modem connected to a
computer and the radio. Abbreviated as TLX or TLX-GW for Globe Wireless.
TUNER : Also known as a coupler, this device matches the antenna to the radio
for maximum radiated power.
USB : The modulation method for a marine HF SSB radio is U pper S ide B and.
VOGAD : a
V
oice
O
perated
G
ain
A
djustment
D
evice used in the microphone
audio circuit.
VSWR : V oltage S tanding W ave R atio, this measurement figure helps determine
how well the radio is matched to the antenna system.