d.
Vertical dispersion angle:
[one] [1.57] [2] [_____] rad
[57]
[90] [115] [_____] degrees
e.
Axial sensitivity:
Minimum of [57] [60] [_____] dB
f.
Line transformers power rating:
At least 4 watts
][2.1.4
Type 4 System:
Paging System
**************************************************************************
NOTE: Select the appropriate paragraph and its
following subparagraphs for the features desired.
Delete paragraphs describing the features not
required. System capacity should include future
expansion requirements.
**************************************************************************
Provide paging system including amplifier, preamplifier, control panel,
speakers, microphone, and interconnecting cables. All speakers shall
operate from a [70] [25] volt distribution system. System shall be solid
state, and shall be integrated design of a single supplier.
2.1.4.1
Preamplifier/Mixer
Provide preamplifier/mixer either separately or as an integral part of
power amplifier. If separate, it shall be completely self-contained,
requiring only a 120 Vac power source. Provide controls which are front
panel mounted, and include ON/OFF switch with power on visual indicator.
Preamplifier shall employee only solid state devices and shall be as a
minimum conform to the following specifications:
a.
Inputs: Microphone:
Low impedance, 150 ohms nominal
Auxiliary:
High impedance, 500,000 ohms or greater
b.
Signal-to-noise ratio:
60 dB or greater at rated output
c.
Frequency response ratio:
Plus or minus 2 dB from 20 Hz to 20,000
Hz
d.
Total harmonic distortion:
Less than 3 percent at rated output
power
e.
Output:
Shall be sufficient to drive power amplifier to rated
output
2.1.4.2
Power Amplifier
Power amplifier shall employ only solid state devices and shall be as a
minimum conform to the following specifications:
**************************************************************************
NOTE: To specify proper power rating of amplifier,
allow 1 watt for each cone type speaker and 1.5
watts for each horn type. Special circumstances may
dictate greater power requirements.
**************************************************************************
Provide controls which are front panel mounted, and include ON/OFF switch
SECTION 16822N
Page 13
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