SG-2000 MANUAL
12
The SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
©1995, SGC, Inc.
TEL: (206) 746-6310 FAX: (206) 746-6384
4.0 About the SG-2000
The basic SG-2000 is really two units, which may be easily separated. One unit is what
is called the Radio or RF unit. This contains the receiver and the transmitter's exciter
and linear power amplifier modules. In addition, it contains the SG-2000's main
microprocessor.
The second unit, normally supplied attached to the radio unit, is called the control head.
In it are audio amplifiers, the radio's frequency and channel displays, a keyboard to
control radio functions and another microprocessor which "talks" to the main radio
unit.
Control Head Control Head
SG-2000 RF Unit
RS-232 (9600 baud)
Serial Port for
computer
RS-422 (9600 baud) Serial Bus
Audio wiring at 600 ohms plus
To additional heads
(8 maximum)
One control head may be attached to
the SG-2000 RF unit. Up to seven
others may be located up to 50 meters
away from the RF unit using 10-conductor
cable.
4.1
Receiver Signal Path
The receiver section, located in the main radio unit, features signal up conversion (from
82 to 88 MHz) to achieve maximum image rejection and to allow wide band processing
of signals. Then the signal is converted down to 10.7 MHz where an extraordinarily
sharp crystal filter removes all unwanted signals, including strong unwanted signals
which have not been eliminated by the 82-88 MHz filters.
The 10.7 MHz signal is further amplified and is then decoded by one of the two
detectors in the radio. For single sideband, CW (Morse Code), and data operations, a
product detector is used. For AM, the SG-2000 provides one of the few "true AM"
detectors available today. This provides for extremely clear reception and excellent