Williams Sound FM 557 Large-Area Dual FM Plus and Wi-Fi Assistive Listening System with FM T55 Transmitter, (4) PPA R37N Receivers,

Williams AV FM 557 Large-Area Dual FM Plus and Wi-Fi Assistive Listening System with FM T55 Transmitter, (4) PPA R37N Receivers, (4) EAR 022 Earphones, (2) NKL 001 Neckloops and IDP 008 ADA Wall Plaque

• Includes: (1) FM T55 Transmitter, (4) PPA R37N Receivers, (4) EAR 022 Surround Earphones, (2) NKL 001 Neckloops and (1) IDP 008 ADA Wall Plaque

• Operating Frequencies: 72.1-75.9MHz , 17 wideband channels (selectable)
• Frequency Accuracy: ±2 ppm stability
• Deviation: ±75kHz maximum
• Pre-Emphasis: 75 microsec
• Frequency Response: 31-16000Hz, ±3 dB
• Signal-to-Noise Ratio: 67dB Transmited RF
• Total Harmonic Distortion: Less than 0.25% @ 1kHz (RF output)
• Common Mode Rejection: 57dB @ 1kHz, Mic or Line
• Rack Mount: Standard 19" Rack, one EIA rack space high, 1/2 space wide
• Ethernet: RJ-45, 10/100 Base-T IEEE 802.3 compliant, unique MAC address
• Weight: 3.2 lbs

• Channels: 17, accessed via seek button in battery compartment
• FM Deviation: 75kHz
• De-Emphasis: 75µS
• AFC Range: ± 120kHz
• Sensitivity: 2µV at 12dB Sinad with squelch defeated
• Input Overload: 100mV
• Frequency Response: 200–15kHz
• Modulation: FM, +/- 75kHz peak deviation
• Signal-to-Noise Ratio: 65dB min @ 100uV
• Receive Antenna: Integral with earphone/headphone cord
• Audio Output: 35 mW, peak into 16 ohms
• Output Connector: 3.5mm stereo/mono phone jack
• Weight: 4.6oz

• Plug: 3.5mm mono
• Driver Size: 23mm
• Nominal Impedance: 32?
• Freq. Response: 20-20kHz
• Max Power Input: 30mW
• Sensitivity: 118dB @ 1kHz
• Weight: 15g