GAI-Tronics 297-103RT4 Retrofit S.M.A.R.T. Externally Powered Emergency Phones - Manual (Page 11)

P AGE 10 of 17
R ETROFIT E XTERNALLY P OWERED S.M.A.R.T. E MERGENCY P HONES Pub. 42004-379A
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08/06
Audio Level Adjustment
The speaker volume and microphone sensitivity are factory set to nominal levels that are acceptable for
most installations. However, some installations may require adjustments for the speaker and microphone.
Both the speaker and microphone adjustments are made using potentiometers on the emergency phone
PCBA. R106 is the speaker volume adjustment, and R88 is the microphone sensitivity adjustment. Refer
to Figure 8 for the potentiometer locations.
Special care must be given to adjusting the speaker volume and microphone level. If one or both of the
levels are set too high, acoustic feedback (howling) can occur. If acoustic feedback occurs, we
recommend returning both potentiometers to the nominal factory settings and beginning the adjustment
again from this point.
Additionally, the acoustical characteristics of the emergency phones are different both when the front
panel is removed from the enclosure and when the front panel is tightly mounted in the enclosure. After
making any volume adjustments, we recommend mounting the front panel to the enclosure and again
testing the phone.
Auxiliary Output
Each telephone includes one isolated solid state switch capable of switching a maximum of 48 V dc, 125
mA or 28 V
RMS
ac, 80
RMS
mA. TB2 (OUT1) on the emergency phone PCBA provides the connections for
the auxiliary output. Refer to Figure 8 for the location of TB2.
The auxiliary output allows peripheral equipment, such as beacons, video cameras, and alarm generators,
to be activated when the EMERGENCY push button is pressed. The relay remains energized for the
duration of the emergency call.
In many applications, the auxiliary output is used to operate a GAI-Tronics Model 530FB/531A Beacon
(sold separately). For connection details, please refer to the Model 530FB/531A installation bulletin
included with the beacon. Information is also available at www.gai-tronics.com.