The 525N is a third-generation AM Modulation Monitor from Inovonics. It can accept either a direct feed from the transmitter, or function as a precision Reference Receiver to give accurate off-air measurements reflecting ATU, phasor and antenna parameters. A proprietary phase-locked synchronous detector provides precise demodulation, rejects interference, and recovers only the amplitude-modulated component of HD Radio™ ‘hybrid digital’ transmissions. The 525N is also compatible with power-saving MDCL operation. Although the 525N maintains full wideband response for measurement, it features user-selectable audio-monitor cutoff characteristics to mitigate noise or to simulate the response of consumer radios. IP connectivity with full SNMP support gives the user total access to the unit from any computer, tablet or mobile device. Setup, metering, alarms and audio monitoring are all available from the remote monitoring point. The 525N is supplied with a large-aperture, weatherproof loop antenna.