Intercommunication Amplifier

stations with [stainless steel] [anodized aluminum] face plates with

temperproof mounting screws and [galvanized steel] [aluminum] backbox. [A

"call-in" switch mounted on a faceplate to provide selective call-in master

station shall be provided as an integral part of the remote station.]

Remote station shall provide speakers with a minimum sensitivity of 40 dB

for speakers less than 200 mm 8 inches in diameter and at least 45 dB for

speaker 200 mm 8 inches or greater.

2.1.3.3

Intercommunication Amplifier

Intercommunication amplifier shall as a minimum conform to the following

specifications:

a.

Output power:

[2] [_____] watts rms or greater

b.

Total harmonic distortion: Less than 5 percent at rated output

power with a load equivalent to a load equivalent to one station

connected output terminals

c.

Signal-to-noise ratio:

60 dB or greater at rated output

d.

Frequency response ratio:

Plus or minus 2 dB from 200 Hz to

10,000 Hz

2.1.3.4

All-Call Amplifier

All-call amplifier shall as a minimum conform to the following

specifications:

a.

Output power:

Minimum of [0.5] [_____] watt rms for each station

b.

Total harmonic distortion: Less than 5 percent at rated power

with a load equivalent to [____] stations connected to output

terminal all-call mode of operation

c.

Signal-to-noise ratio:

60 dB or greater at rated output

d.

Frequency response ratio:

Plus or minus 2 dB from 50 Hz to 10,000

Hz

2.1.3.5

Horn-Type Loudspeakers

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NOTE: Use 57 decibels for axial sensitivity of

bi-directional and compound diffraction horns.

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Horn-type loudspeakers shall be provided with line transformers and

mounting brackets and shall be as a minimum conform to the following

specifications:

a.

Frequency response ratio:

Plus or minus 3 dB from 250 Hz to

10,000 Hz

b.

Power rating:

[25] [_____] watts

c.

Horizontal dispersion angle:

[one] [1.57] [2] [_____] rad

[57]

[90] [115] [_____] degrees

SECTION 16822N

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