GAI-Tronics DHS-201 Digital Intercom Stations - Manual (Page 14)

Pub. 42004-453C
M ODEL DHS/DHF 200 S ERIES D IGITAL I NTERCOM S TATIONS Page 12 of 25
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System
This station requires a two-conductor twisted pair cable run between the station and the central control
unit. 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 No. 22 AWG (0.325 mm 2 ) No.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 )
Power Three-conductor, No. 18 AWG (0.823 mm 2 )
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 )
Speaker cable Two-conductor twisted pair, No. 18 AWG (0.823 mm 2 )
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.