Product Specification Sheet APS380

Rev. 07/2013

SM202 Duo-Com™ Master Station with built-in electronic chime

This Specsheet is for a product which is discontinued. Please contact us for alternative products.
  • Requires only 2-Wires for Intercom and Chime from Remote
  • Powers from 4- 'C' Batteries or low-cost plug-in adaptor
  • Built-in Electronic Chime Signal
  • Built-in Momentary Electric Door Release Push-button
  • Modern Styling
Architects' And Engineers' Specifications

The intercom master station system shall be Alpha Communications® Duo-Com™ model SM202 or approved equal. Master station shall be surface mount and shall include a built-in voice amplifier, electronic chime signal and momentary electric door release push-button. Master shall be powered by 4- 'C' batteries (supplied by the customer) or an optional model SS6C plug-in power supply. Outdoor remote station shall be the model OR202

Where required, the outdoor remote shall be protected from vandalism with the addition of a model CP202SS Stainless Steel cover plate assembly. 

Contractor shall furnish and install a (compatible) electric door release, and related door release power supply, if required. 

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

SM202 Duo-Comâ„¢ Master Stations

The Alpha Communications® (SM202 Duo-Com™) series intercom system is our most economical master/remote intercom for door entry or any other application requiring a single master and a single remote intercom station. 

The SM202 master station has a built-in amplifier and electronic chime. It easily mounts right on the surface of the wall and can directly replace an existing door chime or door bell, on the existing 2-wires! A built-in momentary door release button allows hook-up to your own low voltage door opener (depending upon transformer used). The optional PK407A door opener relay allows connection to other voltages and types of door openers. 

The SM202 master is sold as a stand-alone item, or prepackaged in our SM202K intercom kit.



SM202: Height: 7.50" (191mm)
Width: 5.13" (131mm)
Projects: 1.63" (42mm) from surface of wall
Wiring Requirements

Run a 2-conductor twisted pair #22AWG cable from the SM202 master to the OR202 remote station, up to 250 feet. For runs up to 1,000 feet, use a 2-conductor (shielded) #18AWG cable. Run a separate 2-conductor #18AWG cable from the door opener transformer to the SM202 master up to 50 feet. Run a separate 2- conductor #18AWG cable from the SM202 master to the optional electric door opener, up to 50 feet. 

NOTE: the audio and door opener and transformer cables must be in separate jackets and not in the same cable jacket. See system wiring diagram for more complete wiring information.

Optional Components

  • PK407A Specialty door release relay for connections to magnetic door locks, or reverse-action door openers, or door openers with voltages other than 16VAC or 24VAC.

Alpha Communications
42 Central Drive • Farmingdale • NY • 11735-1202 • Phone: (631) 777-5500 • Fax: (631) 777-5599
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Due to continuous product improvement, all colors, sizes, materials, finishes and specifications are subject to change without notice.