Belar: "When accuracy counts, count on Belar"


FMSA-1 photo


The FMSA-1 is a DSP-based, microprocessor-controlled, FM Stereo Modulation Monitor/ Analyzer. The FMSA-1 digitizes the composite baseband signal and decodes the stereo multiplex portion using digital signal processing techniques. Unlike an analog design, a DSP-based design is immune to variations due to temperature or the aging and tolerance of components. As a result, the FMSA-1 attains superlative performance while requiring virtually no adjustment. By employing linear-phase FIR filters, the FMSA-1 eliminates phase distortion in the recovered audio. This permits unprecedented accuracy in measuring modulation peaks on the Left, Right, L+R and L-R signals. These performance advances result from the mathematically pure demodulation algorithm implemented by the FMSA-1 processors.

All FMSA-1 measurements--peak modulations, injections, and dB ratios--are displayed on digital readouts. The readings can also be viewed remotely on a virtual front panel when the FMSA-1 Digital FM Stereo Monitor/Analyzer is used in conjunction with the Belar Wizard FMMA-1 FM Digital Modulation Monitor/Analyzer and a personal computer. Remote operation of the FMMA-1/FMSA-1 pair in tandem with an automatic audio analyzer facilitates a fully automated stereo proof-of-performance.

The FMSA-1 features user-defined parameters and settings for maximum flexibility. The two UP/DOWN menu keys are used to cycle the 16-digit alphanumeric display to the desired menu; the UP/DOWN parameter keys are then used to select the desired setting. The configuration can be saved to non-volatile memory in the unit in the event of a power loss.


When used in combination with the Belar FMMA-1 Wizard and The Wizard Software, the FMSA-1 offers unusual flexibility in remote as well as on-site monitoring. The Wizard Software transforms an ordinary PC into a powerful tool for the real-time graphic display and logging of modulation parameters. When tied to the companion FMMA-1--directly or through modems and a standard phone line--the PC can interrogate and control all functions of the FMSA-1. Passwords allow the restriction of control at three levels.

With the addition of the Belar RFA-4 Frequency Agile FM RF Amplifier to the monitoring system, The Wizard Software permits the remote selection of monitored stations from among 10 preset frequencies or those entered directly by the user. Call letters of preset stations appear on the computer screen for easy identification. Users may also write their own software for controlling and interrogating the FMSA-1 directly through its own RS-232 port.




Input Level	                        2.8V- 5.7V P-P composite

Input Impedance                         100 k , unbalanced, BNC connector

Display                                 Two large 3 digit 7 segment LED for

                                          Left and Right (or L+R and L-R) Modulation

                                          16 segment alphanumeric LED display

                                          for menus and parameters

Modulation Display Range                0-127% in 1% increments, accuracy 0.5%

Pilot Injection Range                   0-12.7% in 0.1% increments


  Pilot                                 2V P-P, 500 , unbalanced

  Left and Right 

    Audio (Program)                     +10 dBm, 600 , balanced

    Test                                2.5 Vrms, 75  unbalanced

    Scope                               1.3 Vrms, 75  unbalanced

    Digital                             AES/EBU, 48 kHz


  Left to Right                         80 dB, 10 Hz to 15 kHz

  Right to Left                         80 dB, 10 Hz to 15 kHz


  L + R to L - R, 

  L + R to L - R (matrix)               80 dB min

  L + R to L - R,

  L + R to L - R (direct)               90 dB min

  SCA to L + R                          90 dB min

  SCA to L - R                          90 dB min

  SCA Interference                      90 dB min

Serial Interface                        RS-232

Unit Interface                          Wizard Standard Interface

Remote Meter Outputs:

  Left Channel Analog Meter,

  Right Channel Analog Meter,

  Pilot LED, Pilot Relay                for interface to

                                           Model MP-15 Analog Meter Panel (optional)

Audio Output Specifications

  Frequency Response,

    Left and Right                      0.05 dB flat, 50 to 15 kHz

                                        0.25 dB de-emphasized

  Signal-to-Noise Ratio, with de-emphasis

    Left and Right                      90 dB

  Harmonic Distortion                   0.01% max, 50 to 15 kHz

  Intermodulation Distortion            0.01% max (SMPTE)

Dimensions                              1 EIA Rack Unit

                                        1.75"H x 14"D x 19"W

Power Requirements                      25 watts, 100-240 VAC, 50-60 Hz

Shipping Weight                         12 lbs

© Copyright 2000 Belar Electronics Laboratory, Inc. All rights reserved. Specifications subject to change without prior notice.

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