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.

UHF wireless IFB Transmitter basestation with 256 selectable frequencies at 100kHz increments. Stand alone or rack mountable with the PRK-2 kit. (486.4 - 691.1 MHz). Non-RoHs

Operating Frequencies
486.4 to 691.1MHz

Block 19: 486.4 to 511.9 MHz

Block 20: 512.0 to 537.5 MHz

Block 21: 537.6 to 563.1 MHz

Block 24: 614.4 to 639.9 MHz

Block 25: 640.0 to 665.5 MHz

Block 26: 665.6 to 691.1 MHz

Frequencies Channels (per block): 256
Channel spacing: 100 kHz (0.1 MHz)
Spurious & Harmonic Suppression: 37 dBc above 1 GHz
Frequency Stability: ?.001% (10 ppm) @ 25?C
Temperature Stability: ?.001% (10 ppm) from -30? C to +50? C
Channel Selection: Momentary pushbutton switches, TUNE UP and Down
Compatibility Modes: IFB, Digital Hybrid Wireless; 400 Mode, 200 Mode, 100 Mode, Mode 3, Mode 6
Pilot Tone: 29.997 kHz IFB Mode, 32.765kHz; 200 Mode, 400 Mode step selected, 32.768kHz Mode 6
Modulation: FM, ?20 kHz deviation IFB & 100 Mode, ?75kHz 200 & 400 Mode, ?50kHz Mode 3 and Mode 6

Audio Frequency Response

100 Hz to 8 kHz

?1 dB, IFB MODE system response (see Rolloff)

30Hz to 20kHz ? 1dB

200 & 400 MODE system response (see Rolloff)

Rolloff: Low frequency audio rolloff is Menu selectable for 3 dB down at 35 Hz or 50 Hz
Signal to Noise Ratio: 90 dB typical ("A" weighted)
RF Power Output: 250 mW (nominal)
Output Impedance: 50 Ohms
Audio Input Levels: 0 dBu for Line, RTS1 & RTS2, -10 dBu for ClearCom, and -42 dBu mic dry inputs, +/-50VDC max
Audio Input Config: Balanced and Unbalanced, rear panel selectable for Line, Mic, RTS 1, RTS 2 and ClearCom
Audio Input Impedance: Greater than 2 K balanced, greater than 1K unbalanced at any gain setting
Control Range: -18 dB to +24 dB (0 dB nominal center), software selectable
Audio Input Jack: Standard XLR female connector
Input Power: 12 to 14 VDC typical, 200 mA max; Max input range 6 to 18 VDC
Power Input Jack: Coax type, locking LZR RL26AE
Indicators: Backlit Liquid Crystal Display. Displays modulation meter, frequencies, modes, rolloff, audio level, and tuning groups

Front Panel Controls

MENU momentary pushbutton switch

Power OFF-TUNE-XMIT, 3 position slide switch

Select Up momentary pushbutton switch

Select Down momentary pushbutton switch

Rear Panel Controls: Input Mode Select, 4 section DIP switch
Weight: 9oz
Size: 5.25" long (including connectors) x 3.25" wide x 1.25" high
Emission designator: 180KF3E

The T4 IFB transmitter is FCC type accepted under Part 74:470 - 608MHz and 944.1 - 951.9 MHz