The 525N is also compatible with energy-saving MDCL operation. Although the 525N maintains full broadband response for measurement, it has user selectable audio monitor cut-off characteristics to mitigate noise or simulate the response of consumer radios.
IP connectivity with full SNMP support gives the user full access to the unit from any computer, tablet or mobile device. Configuration, measurement, alarms and audio monitoring are all available from the remote monitoring point.
The 525N is equipped with a weatherproof, wide-opening passive AM antenna.
- Accurate and simultaneous display of positive and negative peak modulation with peak density histogram
- Absolute limit and user programmable peak blinkers
- Calibrated RSSI signal strength display and asynchronous noise reading
- Alarms for low signal, audio loss and overmodulation with panel indicators and "tally" closures
- Full web interface offers full remote control of all configuration parameters, measurement, alarms with streaming audio recording and monitoring
- 5 preset stations
- Channel spacing 10kHz / 9kHz
- Balanced audio output
- Supplied with external passive AM antenna
- Headphone jack
Single conversion superheterodyne; 300 kHz IF; synchronous I / Q phase lock detector.
The 75 ohm antenna input (F) connects to the supplied passive wideband AM loop antenna. Cable is not included, but you can use up to 100 feet of RG-6 CATV coaxial cable for general use. A short wire antenna may prove adequate in high signal areas that suffer from minimal interference. A high level 50 ohm (BNC) input accepts a direct RF sample between 1V and 7V rms / 3V - 20V pp.
Tunable via the front panel menu or the Web interface:
- 520 kHz to 1720 kHz in 10 kHz increments
- From 522 kHz to 1719 kHz in 9 kHz steps Five station memory buttons / web presets are available.
Carrier amplitude demodulation extends to 10 kHz, ± 0.2 dB. The measurement is not affected by user selectable audio cut.
User selectable "FLAT" response or limited to programmable 1 kHz intervals between 10 kHz and 2 kHz.
A menu command activates the NRSC's "truncated" 75μs de-emphasis feature to the audio outputs of the program with any limited audio bandwidth selection.
Typically 0.15% THD at 50% carrier modulation; <0.5% at 99% modulation
The front panel bar graph reading that responds to peaks shows both positive and negative modulation peaks simultaneously, with extended persistence of the highest recent peak value. The measurement resolution is 1% between 50% and 100% (negative) and 50% to 140% (positive) modulation and 2% between 20% and 50% modulation.
RSSI and noise display
The modulation display can be switched to show the input carrier dBuV level (RSSI) and a relative asynchronous noise measurement.
- The absolute limit beacons are factory set at -100% and + 125% carrier modulation.
- A second series of flashers can be programmed by the user to values between -70% and -100% and + 70% and + 140%.
Audio output program
- The program audio output (XLR) on the active balanced rear panel provides + 4dBu from a 200 ohm resistive source.
- Front panel headphone jack (¼ inch, TRS)
NPN open collector transistor outputs (screw terminal block) for low signal, program audio loss and overmodulation. The closing polarity is programmable.
RJ45 jack for remote configuration and operation via TCP / IP; DHCP or static IP with local or remote selection
Web-based remote monitoring of off-air audio
Full network configuration utility that includes dynamic DNS and full SNMP support with downloadable MIB files.
Supports e-mail services and text messages with or without SSL.
105-130 V AC (0.250 A fuse) 210-255 V AC (0.125 A fuse), 50/60 Hz; 10W.
Dimensions and weight
1¾" H x 19" W x 7" D (1U); 9 lbs (shipping).
Operating temperature range 0 ° C - 50 ° C; 95% relative humidity without condensation; up to 3000 meters above sea level.