GAI-Tronics 69460-001 Crew's Quarters Muting Card for Centra-Page Systems - Manual (Page 4)

Pub. 42004-382A
Model 69460-001 Crew’s Quarters Muting Card for Centra-Page Systems Page: 4 of 5
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Operation
Card Indicators
The card contains three indicator LEDs that are visible from the front of the card rack. These LEDs are
used to identify the card functions as follows.
Table 2 - Indicator Functions
LED Color/Position Function
Red (top) 24 V dc power is present on the card.
Green (middle) Audio is present on the speaker output.
Yellow (bottom) One or more of the control inputs is active, which enables the
speaker output.
Speakers
8-Ohm Out Operation
When using the 8-ohm output connections, always use speakers of proper voice coil impedance and
power handing capability. Consult GAI-Tronics Pub. 42004-135 and 42004-220 for more details on
speaker installation and wiring.
70.7 Volt Out Operation
Greater speaker line distances from the central cabinet can be obtained by using the 70.7 V output
connection compared with using 8-ohm output. The individual speaker’s power level is determined by
the tap settings on the line-matching transformer. The use of these transformers allows the speakers to be
placed at longer distances from the central amplifier system without significant power loss.
The sum of the speaker power settings must not exceed the total power available from the amplifier
PCBA. For example, the 69460-001 PCBA’s 70.7 V output (~16 W out with ~27 V dc in) can drive
approximately eight speakers tapped at 2 watts each or four speakers tapped at 4 watts each.