Belar FMMA-1 The Wizard Precision FM Digital Modulation Monitor and Analyzer


Belar FMMA-1


The Wizard is a microprocessor controlled, digital baseband FM modulation monitor/analyzer that precisely measures peak modulation, peaks per minute, average peak modulation, modulation density, and more. The Wizard can operate with an existing modulation monitor, or it can be configured to replace an existing baseband modulation monitor. The Wizard Software (included with The Wizard) and an IBM compatible personal computer enable real-time graphing, logging, and remote operation.

The Wizard features user-defined parameters and settings for maximum flexibility. The two large 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.

Two Composite Loop-thru’s permit you to “touch up” your modulation remotely through the RS-232 port. For example, you could run the output of your stereo generator through loop-through 1, then through your composite clipper (if applicable), then through Loop 2. You now have the ability to raise or lower the modulation going into the clipper, and to raise or lower the modulation coming out of the clipper – remotely, if desired.

A built-in Audio Sentry audio failure alarm alerts you to loss of modulation.

When installed at the transmitter, Option 02 measures RF level, AM Noise, and Synchronous AM noise, eliminating the need for a separate AM Noise detector.



The Wizard Software can operate the FMMA-1 remotely and is also used to display real-time graphs. A direct connection or a pair of 2400-bps modems and a phone line may be used. The software is fully password protected with three levels of access. When used for off-air monitoring with the RFA-4 Frequency Agile FM RF Amplifier, The Wizard Software can be used to control the RFA-4, enabling the operator to select among the 10 preset stations or direct dial the desired frequency. The RFA-4’s programmed call letters will appear on the computer screen for easy identification of the station you are measuring.


Total Peak Modulation in Percent
Peak Modulation expressed in kHz Deviation
Peaks-per-Minute Count
Loop-thru #1 Modulation
Loop-thru #2 Modulation
Peak Average Modulation
Average/Peak Modulation Ratio
Peak Minimum Modulation
AM Noise (with Option 02)
Synchronous AM Noise (with Option 02)
RF Level (with Option 02)
Pilot Modulation (requires FMS-2 or other source of filtered pilot)
Pilot Injection (requires FMS-2 or other source of filtered pilot)
SCA Injection (requires SCM-2 or other source of filtered SCA)

Settable Parameters

Hold Time
Peak Modulation Indicator
Peaks-per-Minute Indicator
Display Hold
Display Blanking
Peaks-per-Minute Duration
Remote Enable
Audio Failure Alarm – Time & Modulation
Loop-thru #1 Gain (+20% Modulation)
Loop-thru #2 Gain (+20% Modulation)
Display Resolution (01% or 1%)
Time Mode (Real/Past)
Peak Weighting (8 time constants)
Calibrator (with Option 01)

Technical Specification

Technical Specification


Large 4 digit LED for Total Modulation,
16 segment alphanumeric LED display for menus and parameters

Composite or 650 Khz IF (with Option 01) for use with Belar RFA-4,   RFA-1A, or DC-4, or RF transmitter sample (with Option 01 and Option 02)

Option 01:            
Precision FM Demodulator with Calibrator

650 kHz IF (From RFA-4, RFA-1A, DC-4, or Option 02)

Two 75 ohm buffered, composite

> 95dB

Distortion (IM):
< 0.003%

Distortion (THD):
Unmeasureable (< 0.01%)

Option 02:  
Down Converter and Synchronous AM Noise Detector

Frequency Range:  
88 to 108 MHz Std. (Specify frequency)

1-10 volts rms, 50 ohms, BNC connector

650 kHz IF, 9-pin D connector to Wizard

> 95 dB

AM Noise Range:  
-17 to -80 dB

Synchronous AM Noise Range:
-17 to -80 dB

Product Resources

Product Resources

Belar FMMA-1 Manual

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