Federal Signal Corporation Smart Siren, Руководство по установке и обслуживанию

Страница: 32 / 52

Chapter 4: Setting the Gain for Radio Rebroadcast and PA
32
PA300-CN Siren Amplifier
Setting the Gain for Public Address (PA)
To adjust the PA gain:
1. Stand outside the vehicle in an enclosed area and press the push-to-talk button on the control pad
microphone. Speak into the microphone in a normal tone of voice.
2.
See Figure 4.1 on page 32. To adjust the PA gain, insert a small screwdriver in the PA gain control port
on the front of the siren amplifier. While speaking into the microphone turn the potentiometer clockwise
to increase the gain to just below the point where audio feedback occurs.
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.
3. See Figure 4.3 on 31. To further adjust the PA gain, insert a small flat-head screwdriver in the PA gain
control port (
PA VOL,
) on the back of the control pad. Turn it counter-clockwise while speaking into the
microphone to increase the gain to just below the point where audio feedback occurs.