Features

• Complete set of metering and measurement tools to ensure FM broadcast regulatory compliance worldwide

• Separate inputs for Antenna, High Level ʻ direct ʼ 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

• Composite and Balanced analog Left and Right line outputs

• Front panel metering for subcarrier injection levels: 38kHz, 57kHz (RDS), 67kHz, & 92kHz

• Rugged 1/8th inch (3mm) thick aluminum chassis design, fanless, sealed & thermally “burnt in” for maximum durability

• Alarms for Peak Overmodulation, Signal Loss, Program Audio Loss and Multipath

• Rear-panel closures to ground enable remote alarm indications and preset station switching

Specifications

OFF-AIR RECEIVER SECTION

Type

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

Tuning Range

87.9MHz to 108.1MHz in 100kHz increments.

Station Presets

7 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 of typical 3V p-p equating to ±75kHz carrier deviation.

Composite/MPX Metering

58-segment LED bargraph display has quasi-peak response with floating peakhold. 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 off-air 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 deemphasis applied.

Distortion

<0.25%THD at 100% modulation.

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 front-panel button.

Program De-Emphasis

May be turned on and off from front panel (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.

Measurement Filters

• 19kHz Stereo Pilot Tone

• 38kHz Residual Stereo Subcarrier

• 57kHz RDS/RBDS Data Subcarrier

• 67kHz SCA Audio Subcarrier

• 92kHz SCA Audio Subcarrier

PROGRAMMABLE ALARMS

Peak Flasher

Ground-closure output gives remote indication coincidental with the front-panel Peak Flasher.

Program Audio Loss

Front-panel LED and ground-closure (remote) alarm. Programmable from the front panel to indicate when either stereo channel remains 10dB or more below 0dB for a period that may be set between 10 seconds and 2 minutes.

Low Signal

Front-panel LED and remote ground-closure alarm; fixed at a level of incoming RF signal below which modulation measurements are not valid.

Multipath

Front-panel LED and remote ground-closure alarm; fixed at a degree of multipath distortion above which modulation measurements are not valid.

MISCELLANEOUS

Power Requirements

105–130VAC or 210–260VAC, 50/60Hz; 20 watts

Size and Weight

3½”H x 19”W x 12”D (2U); 14 lbs. (shipping)

Environmental

0°C - 50°C operating temperature range; 95% non-condensing relative humidity; up to 3000 meters AMSL