Belar FMSA1

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.

• Total Peak Modulation in Percent or dB

• Left Channel Modulation in Percent or dB

• Right Channel Modulation in Percent or dB

• L + R Modulation in Percent or dB

• L - R Modulation in Percent or dB

• Pilot Modulation in Percent

• Pilot Injection in 0.1 Percent

• Direct Reading Separation in dB

• Crosstalk in dB

• 38 kHz Subcarrier Supression in dB

• All dB measurements can be made with or without de-emphasis.

• Hold Time

• Time Mode (Real/Past)

• Display Hold

• Remote Enable

• Crosstalk (Direct/Matrix)

• 75/50 microsecond De-emphasis