OFF-AIR RECEIVER
Receiver Topology
Single-conversion superheterodyne; 300kHz IF; phase-locked I/Q synchronous detector.
The 75-ohm (F) antenna input connects to the supplied broadband passive AM Loop Antenna. Cable is not included, but up to 100 feet of general-purpose RG-6 CATV coax may be used. A short wire antenna may prove adequate in high-signal areas that suffer minimal interference. A 50-ohm (BNC) high-level input accepts a direct RF sample between 1V and 7V r.m.s. / 3V–20V p-p.
Tuning Range
Tunable via the front-panel menu or the Web interface:
- 520kHz to 1720kHz in 10kHz steps
- 522kHz to 1719kHz in 9kHz steps Five station-memory pushbutton/Web presets are provided.
MEASUREMENT PARAMETERS
Measurement Bandwidth
Carrier amplitude demodulation extends to 10kHz, ±0.2dB. Measurement is not affected by the user-selectable audio cutoff.
Audio Response
User-selectable “FLAT” response, or restricted in programmable 1kHz steps between 10kHz and 2kHz.
De-Emphasis
A menu command switches-in the NRSC ‘truncated’ 75μs de-emphasis characteristic to the program audio outputs with any restricted audio bandwidth selection.
Audio Distortion
Typically 0.15% THD at 50% carrier modulation; <0.5% at 99% modulation
DISPLAYS
Modulation Display
The peak-responding front-panel bargraph readout shows positive and negative modulation peaks simultaneously, with extended persistence of the most recent highest peak value. Measurement resolution is 1% between 50% and 100% (negative) and 50% and 140% (positive) modulation, and 2% between 20% and 50% modulation.
RSSI and Noise Display
The Modulation Display may be switched to show the dBuV level of the incoming carrier (RSSI) and a relative measurement of asynchronous noise.
Peak Flashers
- Absolute-limit flashers are factory-calibrated at –100% and +125% carrier modulation.
- A second set of flashers may be programmed by the user to values between –70% and –100%, and +70% and +140%.
CONNECTIONS
Program Audio Outputs
- The active-balanced, rear-panel program audio output (XLR) delivers +4dBu from a 200-ohm resistive source.
- Front-panel headphone jack (¼-inch, TRS)
Alarms
Open-collector NPN transistor outputs (screw-terminal block) for low signal, program audio loss and overmodulation. Closure polarity is programmable.
WEB INTERFACE
Connection
RJ45 jack for remote setup and operation via TCP/IP; DHCP or Static IP with local or remote selection
Remote Monitoring
Remote Web-based monitoring of off-air audio
Network
Comprehensive network configuration utility including
dynamic DNS and full SNMP support with downloadable
MIB file.
Alerts
Supports email and text message services with or without SSL.
MISCELLANEOUS
Power Requirements
105–130VAC (0.250A Fuse) 210–255VAC (0.125A Fuse),50/60Hz; 10W.
Size and Weight
1¾”H x 19”W x 7”D (1U); 9 lbs. (shipping).
Environmental
Continuous operation at ambient temperatures between 32ºF/0ºC and 122ºF/50ºC; 0-95% relative humidity, non-condensing, altitudes to 10,000ft/3,048m.
