Belar: "When accuracy counts, count on Belar"



The Belar AMMA-2 is a DSP-based microprocessor-controlled, digital AM modulation monitor/analyzer that precisely measures positive and negative peak modulation, peaks per minute, average peak modulation, modulation density, and more. In addition to monitoring standard AM modulation, the AMMA-2 accurately monitors modulation-dependent carrier level (MDCL) AM transmissions. During MDCL broadcasts, the RF carrier level becomes a dynamic component of the AM signal. The AMMA-2 tracks the carrier, capturing the highest and lowest values of the carrier level, as well as the decibel ratio of the carrier high/low. Modulation readings are referenced to the carrier level appropriate for the MDCL system in use. The optional remote meter panel displays positive modulation, negative modulation, and carrier level simultaneously on three large analog meters.

The AMMA-2 features user-defined parameters and settings for maximum flexibility. Two large UP/DOWN menu keys are used to cycle the 16-character alphanumeric display to the desired menu; the UP/DOWN parameter keys are then used to select the desired setting. The unit configuration may be saved to the on-board non-volatile memory so the settings are retained in the event of a power loss.

A noise menu selection displays rms-detected SNR in decibels (flat or de-emphasized) on the front panel.

A carrier cutoff indicator consisting of three front panel LEDs continuously monitors the approach of negative modulation to carrier cutoff.

A unique "Normal Modulation" indicator shows when modulation is falling within user-defined parameters.

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

An RS-232/RS-422 port allows the AMMA-2 to be accessed via personal computer. The ASCII command set, documented in the users manual, provides an easy way for users to write their own command and control software. Alternately, the AMMA-2 will be supported in the future by The Wizard Software, which provides unit control and graphing and logging capability for all the AMMA-2 measurements.

A remote alarm connector consisting of 8 pairs of relay contacts provides alarm status information for hard-wired applications. NRSC de-emphasis may be selected internally by moving a jumper plug.





RF Frequency Range                            150 kHz to 30 MHz
RF Tuning Increments                          1 kHz
RF Sensitivity                                1 to 10 volts rms
RF Input Impedance                            500 ohm or 50 ohm, internally connected

Accuracy                                      1.0%
Display Large                                 Large 3 digit LED for Negative Modulation,
                                              16-character alphanumeric LED display
                                              for menus and parameters

Frequency Response                            0.1 dB, 30 Hz to 10.2 kHz
                                              -3dB @ 11.9kHz
                                              -100 dB @ 16 kHz

Audio Outputs
     Audio Monitor                            +10 dBm, 600 ohm, balanced (XLR), NRSC or Flat
     Audio Test                               2.5 V rms unbalanced (BNC)
     Frequency Response                       0.1 dB, 30 Hz to 10.2 kHz
     Distortion                               less than or equal to 0.1% @ 99% modulation
     IMD (SMPTE, CCIF, DIM)                   less than or equal to 0.1% @ 99% modulation
     Signal to noise ratio                    75 dB
     Signal Delay                             Test: 3 ms., Meter: 90 ms.

Automatic Carrier Level Adjustment range      25-150%

Remote Meter Output                           Jack for optional MP-17 analog remote meter panel

Remote Alarms                                 Relays for Loss of Modulation
                                              Normal, Negative PPM, Positive PPM
                                              Loss of Carrier, Remote, and General alarms.
                                              Relays can be set NO or NC
Serial Interface                              RS-232/RS-422
Unit Interface                                Wizard Standard Interface

Power Requirements                            20 watts, 100-240 Vac 50/60 Hz
Dimensions                                    1 3/4"H x 14"D x 19"W (EIA rack mount)
Shipping Weight                               10 lbs (4.5 kg)

© Copyright 2013 Belar Electronics Laboratory, Inc. All rights reserved. Specifications subject to change without prior notice.

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