Tour Guide FM System

Ideal Use Cases

The Williams AV TGS PRO 738 is a multi-channel FM tour guide system designed to help tour participants listen directly to the guide. It provides 17 wideband channels accessed through the menu and operates on listed frequencies from 72.1 through 75.9 MHz. With a stated range of 150 ft (45 m), it supports guided groups moving through a defined tour area. The channel selection is also useful when operators need to choose among multiple available FM paths.

Why Choose This Model

A 1-inch OLED screen places essential operating details on the unit. Available status information includes the selected channel or frequency, microphone and auxiliary input levels, battery status, microphone mute, channel lock, and dual-preset mode. Up, Down, and Menu buttons provide direct access to transmitter settings. The main push button powers the unit on or off when held for three seconds and toggles microphone mute when pressed and released. A green power LED flashes when the battery is low.

The menu provides controls for volume, auxiliary input level, compression, channel mode, screen timeout, screen brightness, and default-setting restoration. Operators can also choose between channel and frequency display modes.

Installation and Integration

The transmitter accepts an electret microphone through a 3.5 mm mono input with electret microphone bias and an adjustable 25 dB gain range. A 2.5 mm stereo auxiliary input provides an adjustable 60 dB gain range for an additional audio source. The transmit antenna is integrated with the microphone cord, while the receive antenna is integrated with the connected earphone or headphone cord.

The listed headphone connection is a 3.5 mm stereo jack that delivers mono output to stereo or mono earphones and headphones. The supplied earphone is a stereo earbud-style model with a foam cushion, 3.5 mm plug, and 32-ohm impedance. Compatible receivers listed for the system include the PFM R31, PFM R32, PFM R33, PFM R36, PPA R35, PPA R37, PPA R35-8, and PPA R1600.

Performance Highlights

The system uses FM modulation with plus or minus 75 kHz peak deviation and lists frequency stability of ±0.005 percent through a synthesized, crystal-referenced PLL design. RF output is rated at 80 mV/m at 3 m, the maximum allowed by FCC rules. The specified signal-to-noise ratio is at least 65 dB at 1.0 V, while receiver audio output reaches 35 mW maximum at 16 ohms.

Selectable audio compression provides either a 1:1 off setting or a 2:1 on setting. The receiver power-save function enters sleep mode after approximately three minutes without an RF signal. The supplied data identifies two-AA alkaline and rechargeable NiMH battery options, including approximately 50 hours with specified alkaline batteries and approximately 32 hours with specified 1500 mAh NiMH batteries. Another listed two-AA alkaline configuration is rated for up to 30 hours.

What Makes It Different

The combination of 17-channel operation and an information-rich OLED interface gives the operator detailed control without requiring a separate status display. A selectable 17- or 8-channel mode, microphone mute, channel lock, dual-preset status, adjustable input levels, display brightness, and screen timeout provide a broad set of operating controls in the menu.

The listed enclosure uses shatter-resistant PC/ABS plastic with a textured, scratch-resistant aluminum faceplate. The product data also identifies FCC, Industry Canada, RoHS, and WEEE approvals or directives. A specified copolymer case measures 15.7 inches wide by 19.7 inches long by 7.2 inches high externally and weighs approximately 6.6 lb when empty.

Final Assessment

The TGS PRO 738 is a focused choice for FM-based guided listening that requires 17 selectable wideband channels, menu-driven configuration, visible audio and battery status, and a listed 150 ft operating range. Its dedicated microphone and auxiliary inputs, selectable compression, AA battery choices, compatible receiver range, and integrated cord antennas provide a clearly defined operating platform. Williams AV lists a Lifetime PLUS Limited Warranty, with 90 days on most accessories.