FM Digital Frequency Monitor

The Belar FMM-4A is a highly accurate digital FM frequency monitor designed especially for automatic broadcast transmitter monitoring. The counter will accurately monitor FM Carrier, Pilot, and SCA Frequencies. A large 3½ digit LED display provides a range of ±19.99 kHz for Carrier, ±1999 Hz for SCA, and ±10 Hz for Pilot. Front panel LED indicators are provided to warn of low level input or loss of any monitoring frequencies. To prevent false alarms, the FMM-4A inhibits the off-frequency alarms until three successive errors are detected. Two levels of alarm are provided for Carrier deviations. An alarm is also provided to indicate an invalid count, which could result from too low an input level or a malfunction with the counter. An optional alarm relay board is available.

FEATURES

• CARRIER
• • RF or LO and IF Inputs (when RFA-4 or RFA-1A is used)
  • ±1 kHz Off-Frequency Alarm
  • ±2 kHz Off-Frequency Alarm
  • Low-Level Alarm
  • FM Averaging Frequency Switch
• PILOT *
• • ±2 Hz Off-Frequency Alarm
  • Low-Level Alarm
• SCA *
• • ±500 Hz Off-Frequency Alarm
  • Low-Level Alarm
• Invalid Count Alarm
• Large 3½ digit LED display
• Low profile design
• Designed for ATS Operation