Federal Signal Corporation 660100, Installation And Maintenance Manual

Page: 31 / 52

Chapter 4: Setting the Gain for Radio Rebroadcast and PA
31
PA300-CN Siren Amplifier
4. Stand outside of the vehicle and note the volume level of the radio rebroadcast. If the volume is too loud
or too soft, insert a small flat-head screwdriver in the gain control port for RADIO REBROADCAST
on the front of the siren amplifier (Figure 4.2). Turn the potentiometer clockwise to increase the volume
until audio feedback (squeal) occurs or counterclockwise to decrease the volume.
NOTE:
Audio feedback depends upon the microphone gain, open windows, speaker placement, and the
proximity of reflecting surfaces such as walls, buildings, or other vehicles.
Figure 4.2 Gain controls for PA and radio rebroadcast (PA300-CN)
GAIN CONTROL FOR RADIO REBROADCAST
PUBLIC ADDRESS
290A6845
3.
To further adjust the radio gain for rebroadcast, insert a small flat-head screwdriver in the PA gain
control port (
RAD. VOL,
) on the back of the control pad (Figure 4.3). Turn it counter-clockwise while
speaking into the microphone to increase the gain to just below the point where audio feedback occurs.
Figure 4.3 Gain controls for PA and radio rebroadcast (control pad)
PUBLIC ADDRESS
GAIN CONTROL
(SECONDARY)
RADIO REBROADCAST
GAIN CONTROL
(SECONDARY)
PA VOL.
RAD. VOL.
290A6851
5. To turn off radio rebroadcast, press Button 7 .