FM body pack transmitter with OLED display

The Williams AV PPA T46 is a compact FM body-pack transmitter designed to broadcast audio on ADA-reserved frequencies to listeners using compatible receivers. Its OLED display presents operating status and menu information, while dedicated controls provide direct access to power, microphone muting, channel selection, audio settings, compression, and display preferences.

Ideal Use Cases

The PPA T46 is suited to listening arrangements in which a presenter or audio source must transmit spoken or program audio to individual receiver users. It supports listeners using PPA R38 or PPA R37 receivers, with additional compatibility listed for PFM R31, PFM R32, PFM R33, PFM R36, PPA R35, PPA R35-8, and PPA R1600 models. Its body-pack format, battery operation, and 150 ft (45 m) range make it practical when the transmitter must remain with the microphone user.

Why Choose This Model

The integrated OLED display provides detailed feedback without requiring separate monitoring equipment. Status information includes channel or frequency, microphone audio level, auxiliary-input audio level, battery status, microphone mute, channel lock, and dual-preset mode. The menu provides access to channel or frequency display selection, volume, auxiliary input, compression, 17- or 8-channel mode, screen timeout, screen brightness, and restoration of default settings. A green power LED flashes when the battery is low, providing an additional visible warning during operation.

Installation and Integration

The microphone input is a 3.5 mm mono jack with electret microphone bias and an adjustable gain range of 25 dB. The specified microphone type is electret with a 3.5 mm mono plug, and the transmit antenna is integrated with the microphone cord. A separate 2.5 mm stereo auxiliary input offers an adjustable gain range of 60 dB for an additional audio source. The microphone and auxiliary level indications on the OLED display help with monitoring both inputs.

Operation is controlled through a momentary push button and dedicated Up, Down, and Menu buttons. Holding the momentary button for three seconds turns the transmitter on or off; pressing and releasing it toggles microphone mute. A battery-type switch for Alkaline or NiMH operation is located behind the battery-compartment door. With two AA 1.5 V non-rechargeable alkaline batteries, nominal current drain is 75 mA and specified battery life is up to 30 hours.

Performance Highlights

• Transmission range: 150 ft (45 m)
• Frequency response: 180 Hz to 13 kHz, within ±3 dB at 1% maximum THD
• Signal-to-noise ratio: 65 dB typical, transmitted
• Modulation: wide-band FM with 75 kHz peak and 75 µS pre-emphasis
• RF output: 80 mV/m at 3 m, the maximum allowed by FCC rules
• Frequency stability: ±0.005% with frequency synthesis, crystal reference, and PLL

Selectable audio compression provides either a 1:1 setting with compression off or a 2:1 setting with compression on. This selection is available directly through the transmitter menu.

What Makes It Different

The PPA T46 combines body-pack portability with a detailed external interface. Rather than limiting feedback to a basic power indicator, its OLED screen shows channel, audio-level, battery, mute, lock, and preset information. Independent microphone and auxiliary inputs offer separate adjustable gain ranges, while selectable compression and 17- or 8-channel operation provide configuration options for different setups. The enclosure uses shatter-resistant PC/ABS plastic with a textured, scratch-resistant aluminum faceplate. Its black and silver housing measures 4.1 inches long by 2.8 inches wide by 1.1 inches deep and weighs 2.6 oz without batteries.

Final Assessment

The Williams AV PPA T46 brings together FM transmission on ADA-reserved frequencies, a 150 ft range, dual audio inputs, menu-selectable compression, and an informative OLED interface in a compact body-pack design. Up to 30 hours of specified alkaline-battery operation supports extended use, while FCC, Industry Canada, RoHS, and WEEE listings document its stated approvals and directives. The transmitter is covered by a limited lifetime warranty, with accessories covered for 90 days.