Product Specification Sheet APS379

Rev. 07/2013

AA903RK Rack Mount Master Station (RM5000EX / CB901EX Series)

  • Clear two-way communications
  • Total privacy with warning tone
  • Discreet call mode
  • Ringing tone / Voice insert
  • Microphone cut-out / Conference
  • Remote control circuits (doorlocks, bells etc.)
  • Automatic busy call-back
  • Hurry- up tone
  • All/Group calls with reply-back
  • Automatic call redirection
  • Secretary transfer
  • Group hunting / Priority
  • Speed dialing
  • Intersystem mobile radio interface
  • Alarm and program distribution
Architects' And Engineers' Specifications

The rack mount master station(s) shall be Alpha Communications® / Ring model AA903RK or approved equivalent. Master(s) shall have clear twoway communications. Master(s) shall feature a 12-button keypad, and shall require simple home-run wiring. Master(s) shall be rack mounted using a custom-supplied 19" (standard type) equipment rack. Contractor shall provide for adequate ventilation and electrical power, for all equipment mounted in the rack. Unit faceplate shall be a matte black painted aluminum. 

Master(s) shall be used with the RM5000EX and/or CB901 series microprocessor intercom systems. 

Contractor shall observe all local and national electrical and building codes.

AA903RK Rack Mount Master Station

The AA903RK is designed for use as a rack-mounted unit, which will fit into a customer-supplied 19" (standard type) equipment rack. 

The unit features a matte black painted aluminium frontplate with speaker and microphone for normal handsfree speech with a range of approximately 3-5 meters or 10-15 feet. Its keyboard section contains a warning lamp and 12 buttons plus a privacy switch, which also functions as a microphone cut-out switch when pressed during a conversation. 

On the touch-dial keyboard, the left-hand T-button is provided for manual control of a conversation when desired. The X-button is used to cancel a call. 

The station permits the connection of a parallel speaker where additional output is required (loudspeaker impedance 50 ohms recommended). The station is designed to work with the RM5000EX and/or CB901 series microprocessor intercom systems.

Matte Black Painted Aluminum faceplate
Width: 19.0" (483mm)
Height: 5.25" (134mm)
Depth: 1.50" (39mm) behind rack
Operating Voltage:

24V DC+/- 20%

Power consumption:
approx. 5W
Frequency range:
300 - 5000 Hz
Galvanic line:
0 dB (1 mW/600 ohm)
Speech level:
normal -12 dBm
Speech level:
max + 4dBm
Tone signalling:
according to CCITT norms
Loudspeaker impedance:
50 ohms
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Due to continuous product improvement, all colors, sizes, materials, finishes and specifications are subject to change without notice.