INOVONICS 531N FM MODULATION MONITOR: TUNABLE OFF-AIR | 76MHZ – 108MHZ | ALARMS | SCA INJECTION | RDS DECODING | AM NOISE | FULL NETWORK

Features:

• Complete set of metering and measurement tools to ensure FM broadcast regulatory compliance worldwide.
• Separate inputs for Antenna, High Level ʻdirectʼ RF, and composite signal measurements.
• Full-time display of Signal Strength and Multipath effects, plus Synchronous AM noise output (BNC) to validate readings and aid in antenna alignment.
• Synchronous AM Noise Monitoring – an exclusive with Inovonics
• Composite and Balanced analog Left and Right line outputs.
• Front panel metering for subcarrier injection levels: 38kHz, 57kHz (RDS), 67kHz, & 92kHz.
• Advanced Metering includes an FFT Spectrum Analyzer for the MPX, Left/Right XY plots and audio levels over time
• Alarms for Peak Overmodulation, Signal Loss, Program Audio Loss and Multipath.
• Rear-panel closures to ground enable remote alarm indications and preset station switching.
• “Responsive” Remote Control Web interface with live audio streaming.
• SNMP control and support.

Specifications: 

OFF-AIR RECEIVER SECTION

Type

• Double-conversion superhet circuit with proprietary ultra-linear, noise-rejecting pulse-counting FM detector

Tuning Range

• 76MHz – 108MHz  in 100kHz increments

Station Presets

• 6 user-programmable pushbutton presets; local or remote selection

RF Inputs

• F connector for 75-ohm antenna
• BNC connector for high-level 50-ohm RF sample; 1V - 7V r.m.s.

Receiver Sensitivity

• 10μV (10dBf) for 50dB mono quieting; 250μV (60dBf) required for valid Total Modulation reading

Receiver Selectivity

• ±0.25dB, 20Hz - 50kHz; –1.5dB or less at 100kHz (see Figure 1); –35dB (typ) at 200kHz (see Figure 2)

Baseband Output

• BNC composite/MPX demod output; 3Vp-p at 100%-modulation.

RSSI (Incoming Signal Level)

• Independent front-panel LED bargraph metering of the relative strength of the incoming carrier

Multipath Distortion Measurement

• Independent front-panel LED bargraph metering of the relative degree of multipath reception-distortion effects

AM Noise Measurement

• Front-panel metering may be switched to show the relative level of the incidental, synchronous AM noise component of the FM carrier. AM noise is routed to a separate BNC output and also monitored by headphones when selected.

FM BASEBAND MEASUREMENTS

Baseband Input

• Adjustable BNC composite/MPX input to stereo decoder and subcarrier measurement circuitry. Accepts 100%- modulation levels (typical 3V p-p) equating to ±75kHz carrier deviation.

Composite/MPX Metering

• 58-segment LED bargraph display has quasi-peak response with floating peak hold. Switchable between positive deviation, negative deviation and highest of either

Meter Resolution

• 1% accuracy between 80% and 100% carrier modulation; 2% resolution between 46% and 80% (100% = ±75kHz carrier deviation)

Metering Integration

• User-selectable at 0.1ms, 0.2ms, 0.5ms and 1.0ms

Meter Frequency Response

• +0/–1%, 10Hz - 100kHz

Peak Flasher

• Programmable in 1% increments between 95% and 120% of total carrier modulation.

STEREO DEMOD PERFORMANCE

Switch-Selected Composite/MPX Input

• Direct connection to the demodulated output of the offair receiver section
• BNC connector accepts an external baseband input 3V p-p (adjustable) equivalent to full (±75kHz) carrier deviation

Program Audio Outputs

• Balanced XLR Left & Right channel stereo program outputs deliver +4dBm at 100% monaural modulation (±75kHz carrier deviation)
• Front-panel headphone jack

Demod Metering Display

• Dual LED bargraph displays show Left and Right or L+R and L–R demodulated program audio. The display is peak responding between +10dB and –30dB, and average responding between –30dB and – 64dB.

Stereo Audio Frequency Response

• ±0.5dB, 10Hz - 15kHz

Stereo Signal-to-Noise Ratio

• Unmodulated (stereo) carrier noise is better than 65dB below 100% modulation with de-emphasis applied.

Distortion

• <0.075%THD at 400Hz 100% Modulation Mono. No De-Emphasis, unweighted

Stereo Separation

• 55dB, 50Hz - 15kHz with an external composite/MPX input. In the off-air mode, receiver selectivity limits separation to >45dB, 50Hz - 15kHz (see Figure 3).

Stereo Crosstalk

• By the M/S or S/M (stereo-difference) method, >60dB, 50Hz - 5kHz, derated to >45dB at 15kHz with external composite/MPX input. In the off-air mode receiver selectivity limits crosstalk to >50dB, 50Hz - 5kHz, derated to >35dB at 15kHz (See Figure 4).

Stereo/Mono Switching

• Mode switching is automatic with a front-panel indicator; monaural reception may be forced with a front-panel button or from the remote Web Interface.

Program De-Emphasis

• May be turned on and off from front panel or Web Interface (indicator provided); internal jumper selects 50μs or 75μs characteristic.

FM SUBCARRIER MEASUREMENTS

Meter Scaling and Resolution/Accuracy

• 58-segment LED bargraph display measures stereo pilot and subcarrier levels between 2.6% and 14% with 0.2% resolution and accuracy. Injection percentages refer to 100% = ±75kHz carrier deviation.

Metering Characteristic

• Peak-responding in all modes