Clear-Com SB-704

4-Channel Switchboard Main Station

4-Channel Switchboard Main Station - 5-channel X 10 station assignment matrix, no speaker - with built-in 2-amp power supply, rack mount (2RU)

SB-704 includes all of the features of the MS-704, with a 4 x10 assignment matrix in place of the internal speaker (external speaker required for station monitoring). The station features a ten-position slide switch matrix that allows assignment of any of the ten intercom lines to any of the four intercom channels, to an isolated separate party-line, or to an off position.

Product Code: SB704

Technical Details

Technical Specification
Panel Microphone Input
Input Type: Electret
Input Impedance: >=2KΩ
Mic Limiter Threshold: 0dBu ±3dB
Mic Limiter Range (SB-704): >= 15dB

Headset Microphone Input
Input Type: Dynamic
Input Impedance: >= 1KΩ
Mic Limiter Threshold: 0dBu ±3dB
Mic Limiter Range (SB-704): >= 15dB

Program Line Input
Maximum Level before Clipping: >= 20dBu
Input Impedance: >= 5KΩ

Headset Output
Load Impedance: >= 8Ω
Output Impedance: <= 25Ω
Output Limiter Threshold: +5dBu ± 3dB
Maximum Output Level before Distortion: >= 17dBu

Speaker Output
Load Impedance: >= 4Ω
Max Output Level before 1% Distortion: 20dBu ± 2dBu

Party-line Output
Off Noise: < -74dBu
Output Impedance: >10KΩ

Party-line Input
Crosstalk: < -60dB
Max level before Clipping: >= 12dBu
Sidetone Null Capability: > 25dB

Stage Announce/Balanced Line Out
Type: Balanced
Output Impedance: >= 200Ω
Load Impedance: >= 600Ω

IFB/Hot Mic
Type: Unbalanced
Output Impedance: 150Ω
Load Impedance: >= 600Ω

Frequency Response
Panel Mic - Party-line: 600 - 10KHz ± 3dB
Headset Mic - Party-line: 200 - 12KHz ± 3dB
Headset Mic - Line Out: 200 - 12KHz ± 3dB
Program Input - Party-line: 100 - 17KHz ± 3dB
Program Input - Headset Out: 200 - 10KHz ± 3dB
Program Input - Speaker Out: 300 - 10KHz ± 3dB
Party-line - Headset Out: 200 - 10KHz ± 3dB
Party-line - Speaker Out: 300 - 10KHz ± 3dB

Max Distortion
Panel Mic - Party-line: <= 0.5%
Headset Mic - Party-line: <= 0.5%
Headset Mic - Line Out: <= 0.5%
Program Input - Party-line: <= 0.2%
Program Input - Headset Out: <= 0.2%
Program Input - Speaker Out: <= 0.5%
Party-line - Headset Out: <= 0.2%
Party-line - Speaker Out: <= 0.5%

Noise
Panel Mic - Party-line: < -65dBu
Headset Mic - Party-line: < -70dBu
Headset Mic - Line Out: < -55dBu
Program Input - Party-line: < -85dBu
Program Input - Headset Out: < -60dBu
Program Input - Speaker Out: < -60dBu
Party-line - Headset Out: < -50dBu
Party-line - Speaker Out: < -50dBu

Max Gain
Panel Mic - Party-line: >= 37dB
Headset Mic - Party-line: 41dB ± 2dB
Headset Mic - Hot Mic Out: 55dB ± 3dB
Headset Mic - Announce Out: 55dB ± 3dB
Program Input - Party-line: >= -16dB
Program Input - Headset Out: >= 18dB
Program Input - Speaker Out: >= 24dB
Party-line - Headset Out: >= 34dB
Party-line - Speaker Out: >= 40dB

Min Gain
Panel Mic - Party-line: <= 25dB

Mains Power
Input Voltage Range: 100 - 240 VAC
Input Frequency Range: 50 - 60 Hz
Input Power: <= 60 VAC
Output Voltage: 30 VDC ± 0.5V
Output Current per Channel (Continuous): 1.2 A
Output Current per Channel (Peak): 2 A (Do not exceed the 1.2A rating for more than 2 seconds per 1 minute period)
Short Circuit Recovery Time (1st short): <= 0.5 sec
Short Circuit Recovery Time >= 20 shorts in 20sec): <= 20 sec

Station Capacity
Up to 40 RS-601 beltpacks or 10 speaker stations or 12 headset stations distributed over all channels

Rear Panel Connectors
Switched Intercom: (10) XLR-3M (1 per channel)
Intercom: (4) XLR-3M (1 per channel)
Announce Out (1) XLR-3M (audio)
Program In: (1) XLR-3F
Hot Mic / IFB Interface: (1) 1/4 in. (0.64 cm) phone jack
External Speaker: (1) 1/4 in. (0.64 cm) phone jack
Accessory: (1) DB-15F
AC Power: IEC 320 connector

Rear Panel Controls
(1) Power switch
(4) Intercom On/Off Switches

Front Panel Connectors
Panel Mic: (1) 1/4 in. (0.64 cm) panel mounting jack
Headset: (1) XLR-4M

Front Panel Controls & Indicators
(1) Panel / headset mic switch
(1) Mic on button
(1) All talk button
(1) Announce button
(1) Party-line link button
(4) Program ON-OFF-INTERRUPT DIP switches
(1) Program level control
(4) Listen adjust controls
(4) Channel null adjust controls
(4) Channel program feed adjust controls
(4) Talk buttons
(4) Call buttons
(4) Listen buttons
(1) RMK button
(1) Speaker ON-OFF switch
(1) Speaker volume control
(4) Short LEDs
(1) Panel mic gain control
(1) Sidetone adjust control
(1) Headset audio limiter DIP switch
(3) Interrupt enable DIP switches
(4) Auto-call DIP switches
(4) Auto-talk/listen DIP switches
(4) Talk latch disable DIP switches
(4) Line length DIP switches
(10) Channel Assignment Slide switches

Environmental
32 - 122˚F (0 - 50˚C)

Dimensions
19 in. W x 3.5 in. H x 10.5 in. D
(483 mm x 88 mm x 267 mm)

Weight
10.93 lbs. (4.97 kg)