SG-2000 MANUAL
120
The SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
©1995, SGC, Inc.
TEL: (206) 746-6310 FAX: (206) 746-6384
19.0 Accessories
Two major accessories for the SG-2000 are the Digital Selective Calling system —
Exsel-100 — and the Telerex error correcting radio communications data
terminal unit.
19.1
Exsel-100 Selective Calling System
The SGC EXSEL-100 unit is designed to operate with the SG-2000 transceiver but
may also be used with any high quality SSB transceiver. The EXSEL-100 system
may be configured as a standard unit, compatible with GMDSS CCIR-493 series
operation. In addition, the EXSEL-100 may be further configured to operate
under the new advanced protocols used by the Australian Overseas Telephone
service, the so-called OTC Advanced signaling system. This capability will be
especially appreciated by world cruising sail boats and by SGC customers in the
outback of Australia.
CCIR-493 is used internationally under GMDSS, the Global Maritime Distress
Signaling System. All of these systems use Digital Selective Calling (DSC)
operation.
In selective calling, multiple radio receivers are used on a single frequency as a
network configuration. Just as the telephone company assigns a telephone
number to a particular telephone, each receiver in the DSC network is assigned a
distinctive number. The distinctive number of each set is not operator-adjustable,
but is readily changed in a matter of minutes by a qualified technician.
To call a particular unit, the sending operator dials the desired unit's unique code
by setting thumb wheel number switches then pressing a spring loaded SEND
button.
The receiver whose code has been sent will respond with a "handshake" tone so
that the sender knows the call was received. At the distant receiver, a red light
will turn on and stay on until the SEND/RESET button is toggled briefly to
RESET.
The EXSEL-100 Unit is largely immune to false triggering and will operate under
most adverse atmospheric conditions. In fact signaling is often better than voice,
so you should not be surprised if you occasionally receive a call but cannot hear
your party well.