Pro Intercom MS301 Master Station

3-Circuit Intercom Master Station with IFB Functions

The MS301 is a 3-circuit Master Station with a unique hybrid configuration. Microprocessors operate all the switching, routing, and supervision functions while both the audio path and the core power supply remain analog. The result is a station with unrivaled flexibility, muscular reliability, and clean, smooth audio.

Supervision functions include the individual monitoring of each circuit for faults, and reporting such by front panel LEDs.

The 3 circuits can be operated independently or linked in A+B and A+B+C modes. All electronic "housekeeping" functions such as maintaining proper termination impedance are handled automatically.

The MS301 can be used with a headset or handset or may operated in hands-free mode by plugging in an accessory close-talking, noise-canceling goose-neck microphone (available separately) and adjusting sidetone for deep suppression.

Each MS301 circuit can be used either in intercom communications mode or in IFB mode with program ducking.

Program audio can be directed to each circuit, and be independently controlled and visually monitored.

An accessory to the MS301 is the MSM301 which adds 3 additional circuits (D, E and F) all of which have the same capabilities as the original 3.

The MS301 is compatible with most other 200ohm unbalanced party-line intercom devices.

Features:

• Three circuits rather than the usual two.
• Each circuit can be intercom or IFB in any combination.
• Circuits are linkable (A + B) or (A + B + C) with auto termination impedance adjustment.
• Each circuit's termination can be lifted via rear panel DIP switches.
• Independent level control of program audio output for each circuit with an LED VU meter for each.
• Mic switch on each circuit can be tapped for locking or held and released for momentary.
• Internal power supply is linear (except for microprocessor functions) with 2.4A continuous output.
• Toroidal transformer with extensive monitoring and auto-control of overload and heat considerations.
• Full duplex, hands-free operation, even in moderately noisy environments. (with optional gooseneck mic.)
• Paging output (balanced and isolated) on rear panel activated by front panel momentary button.
• Dry contacts on rear panel also closed by page button
• Front panel 4-pin XLR may be used for gooseneck mic. or headset.
• Gooseneck or headset mic. may be dynamic or electret. Lighted front panel switch sets choice.
• Front panel green LED indicates presence of 24VDC across the three circuits.
• Three front panel flashing red LEDs report trouble status of each circuit. Other circuits are not affected.
• System resets when the problem is repaired.
• While switching is all electronic, the audio paths remain analog providing comfortable long-term listening.
• A front panel button initiates 'Override' which overrides front panel controls on LS2 and LS3 loudspeaker stations, restoring preset volume and status.

Specifications:

• Current draw (at 120VAC): 0.14A (no load), 1.05A @2.4A DC out
• Power output: 24 volts DC regulated @ 2.4A continuous
• Line termination: DC: 5KW, 50 Hz-20 KHz: 200‡
• Transducer impedances: Mic: 200 ohm dynamic or 1.2k ohm electret, Earphone: 200~600 ohm Aux. input: Mic level: (-44dBm) 48K ohm, Line level (-24dBm): 1K ohm
• Size (excluding ears) : 17" width x 9.5" depth x 1.75" height (432 x 241 x 44.5 mm)
• Weight: 9.8lbs. 4.5Kg