Amplifier - NH200A
General Information

The NH200A is used with the HT2003/2 series S.T.R. handsets, primarily for use in apartment house intercoms, but can be used for small home and office intercoms.
The Alpha Communications NH200A amplifier/power supplies are used with the S.T.R. HT2003 series 5-wire apartment handset stations to provide intercom amplification and power to operate the electric door opener(s) etc. The NH200A operates on 16VAC (30VA) low-voltage Class II wiring. For permanent transformer mounting use our Model #SS106 (U.L. Listed) transformer. For plug-in transformer connection use our Model #SS146 (U.L. Listed) transformer. The NH200A amplifier/power supply is a compact P.C. board type, with self-stick mounting tabs and mounting holes for surface wall or other types of mounting. Connections are positive screw terminal type, using a barrier type terminal connector strip.


Easily Installs Right on Finished Wall Surface or in Customer Supplied HousingOperates on Safe Low-Voltage Class II WiringClear Voice Fidelity with Adjustable Voice Volume ControlConvenient Barrier Type Screw Terminal Connections


Height: 3.50″ (89mm)
Width: 3.50″ (89mm)
Depth: 0.75″ (20mm) from mounting surface
Volume Control: Adjustable potentiometer built-in.

Connections: Barrier Type Screw Terminal Connectors.

Architects’ and Engineers’ Specifications

The power supply/amplifier shall be Alpha Communications model NH200A, or approved equal. Amplifier shall operate from a 16VAC (30VA) U.L. Listed transformer (SS106 or SS146). All wiring to power supply/amplifier shall be low-voltage Class II wiring, installed as per all federal, state, and local electrical codes. Power supply/amplifier shall surface mount right to the finished wall and shall be installed in a suitable environment that is free from excessive dirt, dust, temperature, humidity,
grease and water. Power supply/amplifier shall provide the intercom amplification and signaling power for proper system operation. For most secure installation, power supply should be installed into a lockable equipment cabinet/housing. Power supply/amplifier shall be installed a safe distance from any source of electrical interference.
Optional Components

DO-001 (or equivalent) 16VAC Door Release.
TU1007A Multi Entrance Audio Adaptor. Used when switching audio (intercom) and door release
between two (2) or more entrance stations. Used in addition to system amplifier. Use
one (1) for (2) entrances, use two (2) for (3-4) entrances, use three (3) for (5-6)
entrances and use four (4) for (7-8) entrances. No additional transformer needed.
R1 Pulsating Buzzer Adaptor. Used when you have individual apartment door pushbuttons
that need to signal (buzz) the apartment handsets. Converts steady buzzer to
pulsating buzzer.
PK407A Specialty Relay Adaptor. Used when connecting a door opener other than a 16VAC
type to system. One (1) required for each building entry door opener.

Amplifier – NH200A
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