FMM-4A FM FREQUENCY MONITOR
Description
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 3112 digit LED dis-play 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 Input or LO and IF Inputs when an 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
Specifications
General
- Frequency Range
- See below
- Display
- Large 3½ digit LED
- Gate Time
- 2 seconds
- Time Base
- 6 MHz
- Time Base Output
- 6 MHz TTL compatible level
- Invalid Count Alarm
- Prevents false counts due to low level or problem in counter
- Level Alarms
- 3 LED Indicators
Carrier
- Frequency Range
- 80 MHz to 120 MHz
- Sensitivity
- RF (LO/IF): (200/100) mV
- Resolution
- ±10 Hz
- Range
- ±19.99 kHz
- Off-Frequency Alarms
- ±1 kHz & ±2 kHz
Pilot
- Frequency Range
- 19 kHz ±10 Hz
- Sensitivity
- 500 mV
- Resolution
- ±0.1 Hz
- Range
- ±10 Hz
- Off-Frequency Alarms
- ±2 Hz
SCA
- Frequency Range
- 67 kHz direct, or follows range of Belar SCM-2 SCA monitor
- Sensitivity
- 500 mV
- Resolution
- ±1 Hz
- Range
- ±1999 Hz
- Frequency Alarms
- ±500 Hz
Packaging
- Dimensions
- 1¾" H × 12" D × 19" W (EIA Rack Mount)
- Power Requirements
- 115/230 VAC, 50/60 Hz
- Shipping Weight
- 10 lbs.
Downloads
Operator Manual
Complete operating instructions, setup information, controls, connections, and technical information for the FMM-4A.
View Manual →