System, Audio – GAI-Tronics DHF-102 Digital Intercom Staitons User Manual
Page 13
Pub.: 42004-383D
M
ODEL
DHS/DHF
S
ERIES
D
IGITAL
I
NTERCOM
S
TATIONS
Page 11 of 24
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System
This station requires a two-conductor twisted pair cable run between the station and the central cabinet.
Cable capacitance is critical to the station performance on long distances. Refer to Table 1 for the
maximum system cable lengths and Table 2 for the recommended cable sizes. Terminate the system
cable on terminal block P44 pins 5 and 6 (Data A and B).
Table 1.
Maximum System Cable Lengths
Cable Capacitance
22 AWG (0.325 mm
2
)
20 AWG (0.519 mm
2
)
30.5 nf/1000 feet (304.8 m)
6562 feet (2000 m)
6562 feet (2000 m)
13.7 nf/1000 feet (304.8 m)
6562 feet (2000 m)/
9843 feet (3000 m) with local 24 V power
9843 feet (3000 m)
Table 2.
Recommended Cable Sizes
Cable Use
Size
System
Two-conductor twisted pair, No. 22 AWG (0.325 mm
2
) is typical
Power
Three-conductor, No. 18 AWG (0.823 mm
2
) is typical
Footswitch, inputs, audio line
Two-conductor, No. 22 AWG (0.325 mm
2
) is typical
Output contacts
Two-conductor twisted pair, No. 18 AWG (0.823 mm
2
) is typical
Speaker cable
Two-conductor twisted pair, No. 18 AWG (0.823 mm
2
) is typical
Audio
External Speaker
If this station is located in a high noise area, an external speaker or horn can be used to broadcast audio
received by this station. Terminate the external speaker or horn on terminal block TB14.
Audio Output to Remote Amps
Audio received by this station can be transmitted to remote amplifier stations for broadcast into high noise
areas. Terminal block TB1 has been provided to connect audio to the remote amplifiers.