Block 25: 640.000 - 665.500 MHz
Wireless IFB (interruptible fold back) systems are used for talent cueing and crew communications in broadcast and motion picture production. In other cases, the IFB system is used by directors and other management to monitor program audio during a production. The IFB PRC-2 receiver provides simplicity and flexibility in a package that is intuitive for untrained users to operate.
The default frequency of the receiver is set by two rotary switches on the side panel. Up to five additional frequencies can also be programmed into the receiver memory using the scan mode. The design uses +/-20 kHz FM deviation for efficient use of the bandwidth, with compandor noise reduction circuitry for an excellent signal to noise ratio. The receiver will drive a wide variety of earbuds, headphones and induction neck loops at substantial levels, with loads from 16 Ohms to 600 Ohms.
The receiver is housed in a rugged machined aluminum package. A spring-loaded belt clip provides a secure mounting on a wide variety of belts, pockets and fabrics.
-Preset (default) frequency can be set without power or transmitter signal
-Frequency agile with 256 frequencies
-Scan mode stores up to five additional frequencies
-Multi-color LED and rotary control for programmingand operation
-High sensitivity for extended operating range indoorsor outdoors
-Rugged machined aluminum housing
-Spring-loaded belt clip
-Attached battery door
-8 hours battery life (alkaline)
-20 hours battery life (lithium)
This particular wireless microphone device operates in portions of the 617-652 MHz or 663-698 MHz frequencies. Beginning in 2017, these frequencies are being transitioned by the Federal Communications Commission (FCC) to the 600 MHz service to meet increasing demand for wireless broadband services. Users of this device must cease operating on these frequencies no later than July 13, 2020. In addition, users of this device may be required to cease operations earlier than that date if their operations could cause harmful interference to a 600 MHz service licensee's wireless operations on these frequencies. For more information, visit the FCC's wireless microphone website at www.fcc.gov/wireless-microphones-guide or call the FCC at 1-888-CALL-FCC (TTY: 1-888-TELL-FCC).
Clear-Com PRC-2 Specifications:
- Operating Frequencies: 537.600 to 767.900 MHz (608 to 614 MHz not avail in USA)
- Frequency control: Crystal Controlled PLL
Sensitivity: 1 uv (20 dB SINAD)
- Signal/Noise ratio: 95 dB A-weighted
- Squelch quieting: 90 dB
- AM rejection: 50 dB, 10 uV to 100 mV
- Modulation acceptance: ±20 kHz
- Spurious rejection: Greater than 70 dB
- Third order intercept: 0 dBm
- Frequency response: 100 Hz to 10 kHz, (±1db)
- Pilot tone: 29.997 kHz, 4.5 kHz deviation (fixedcrystal controlled)
- Audio output: 1V RMS into 50 Ohms minimum
- Antenna: Headphone cable
- Programmable memory: Switches set default frequency
- Up to five additional frequencies can be stored in memory
- Front panel controls: Single knob controls AudioOutput Level, Power on, programming and Scan Frequency Selection
- Indicators: Multi-color LED indicator for power on and battery status.
- Blinks to indicate channel number and during scanning.
- Power requirement:
- 9V alkaline battery lasts about 8 hours
- 9V lithium battery lasts about 20 hours
- Power consumption: 60 mA
- Weight: 7.3 oz with battery
- Size: 3.6 x 2.4 x 0.8 inches (housing only)
- Belt clip and knob extend beyond the housing