Hal Communications ST-6000, Instruction Manual

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3-2
3.2.2 Audio Output Connection
A factory-prepared cable is likewise provided for connection of the tone keyer output of the ST-
6000 to the station transmitter. This cable also has a phono plug connector which may be used or
removed as the particular connections dictate. The output level of the tone keyer is adjustable
with an internal control over the range of –40 dBm to 0 dBm. See section 4.13 of the operations
section for proper adjustment procedures. If a different audio output cable is required, see sect ion
3.3 for proper preparation procedures.
3.2.3 Loop 1 Cable Connection
There are three ways in which current-loop operated devices may be connected to the ST-6000;
"Loop 1", using the "Main" transistor keyer, "Loop 2", using the "Auxiliary" transistor keyer, and
"Loop 3", a jumper connection in series with the internal 60 mA loop power supply. The factory
supplied cables and jumper plugs are arranged so that the internal loop power supply, "Loop 3"
jumper, and "Loop 1" main keying transistor are series connected. "Loop 2" is not connected with
the standard cables and plugs. Alternate applications of the loop connections are discussed in sec-
tion 3.3.1. Current-loop sensing devices such as teleprinters and electronic displays and keyboards
can be connected to the nominal 60 mA loop circuit using the cable labeled "Loop I". If the device
is polarity sensitive (such as the DKB-2010 keyboard and the DS-3000 KSR Terminal), the white
wire is the "positive" connection and the black the "negative". The shield of the cable is NOT con-
nected in the loop circuit but is connected to the ST-6000 cabinet. The shield wire should therefore
be connected to the cabinet of the teleprinter or electronic device as a safety ground. A typical
connection to a 60 mA teleprinter is shown in Figure 3.1. Notice that the selector magnets and
keyboard contacts of the machine are series connected. Also, since the standard cables and jump-
ers connect the ST-6000 internal loop supply, an external loop power supply should NOT be includ-
ed in the loop circuit. Additional TTY equipment can be connected in the loop by breaking the
jumper on the LOOP 3 plug and series connecting the devices. On the LOOP 3 plug, pin 1 is posi-
tive, Pin 3 is negative, and pin 2 cabinet ground. Other loop connections possible with the stand-
ard cables are shown in Figure 3.2. Alternate loop connections are discussed in section 3.3.1.
3.2.4 Motor Power Connection
The power for the teleprinter motor can be supplied by the MOTOR connector of the ST-6000.
The power to this connector is controlled by the autostart relay of the ST-6000. The TOTAL current
supplied by this receptacle should not exceed 10.0 Amperes. The following precautions should be
observed when using the MOTOR receptacle:
1. The power to the MOTOR receptacle is NOT fused in the ST-6000. The user should be sure
that any device attached to this connector has its own fuse protection.
2. The AC voltage furnished on the MOTOR receptacle is the SAME as the AC power line volt-
age supplied to the ST-6000; if the ST-6000 is operated from a nominal 240 VAC power
line, the MOTOR receptacle also furnishes 240 VAC.