Product Specification Sheet APS192

Rev. 07/2013

TTU-4 High Security 2-Way Talk-Thru Communications System

TTU-4 High Security Low-Profile
2-Way Talk-Thru Electronic
Communication System
  • Clear, 2-way hands-free voice communication (halfduplex VOX).
  • Quality electronic design and engineering.
  • Avoid shouting, repetition, misunderstanding.
  • No gooseneck microphone and no external controls.
  • Rugged, tamper-resistant materials.
  • Simple, one-person installation. No need to cut a hole in the barrier.
  • Compact, contemporary design. Fits any decor.
  • Export models available.
  • Made in U.S.A.

Talk-Thru systems are shipped complete with mounting hard ware, instructions, and power supply (AC operated unit), or charger (battery operated unit).

Electrical Specifications

Audio Frequency Response:  Selectively shaped for maximum voice intelligibility
Audio Power:
2 watts per amplifier
Less than 2%
Listen Mode:
20 dB compression
Talk Mode:
Half-Duplex (VOX)
Low-Z dynamic and electret
Power Supply:
Input: 120 VAC, 60 Hz, Output: 15 VDC, 175mA

Mechanical Specifications

Outside Assembly:
Machined aluminum, anodized finish, tamper-resistant
Inside Assembly:
Machined aluminum, anodized finish, tamper-resistant
Size (both assemblies): 
2.375" H x 12.50" W x 2.375" D
2.50 lbs.
Panel Controls:
No external controls

Low-Profile Voice Communication System.

Ideal for High Security Locations

The TTU-4 Talk-Thru communication system is particularly suitable for low ambient noise environments that require an unobtrusive, yet tamper-resistant voice communication system. It features half-duplex (VOX) operation which allows both parties to talk and listen without using any pushbuttons or controls, for easy, natural conversation. 

The TTU-4's counter-mounted design eliminates the need for cutting into a barrier. It's low profile installation adds a personal dimension to such situations as inmate-to-visitor communications. All components including the microphones are housed in the sleek, compact units to avoid for hazards that might be encountered in a high-security environment.

How It Works...

The TTU-4 incorporates the same high-quality electronics as the basic (Norcon) patented model TTU-1 Talk-Thru system, except it is a half-duplex system, enabling the attendant and the customer to talk without pressing any buttons or controls. 

The TTU-4 provides clear communication, shaping the sound for maximum intelligibility. Its compression circuitry decreases loud, annoying sounds. Since the TTU-4 is designed for applications in security areas, all controls and microphones are recessed to minimize unauthorized adjustment and tampering. All exposed hardware is tamper-resistant.

How To Install...

The TTU-4 comes ready to operate. The prism units are quickly and easily mounted on the counter-top on opposite sides of the barrier. They can be positioned back-to-back (as shown) or randomly. The unit with the controls goes inside the booth; the unit without controls is mounted outside the booth. There are two ways to install the TTU-4: either run the cable between the units through a small hole in the barrier, or under the counter-top (as shown on next page).

The TTU-4 uses a continuous-duty, 117-Volt power supply which is stepped down to 12 Volts.

Mounting Details
Alpha Communications
42 Central Drive • Farmingdale • NY • 11735-1202 • Phone: (631) 777-5500 • Fax: (631) 777-5599
TOLL-FREE: (800) 666-4800 • Web: • Email:
Copyright© 1998-2020 Alpha Communications® - All Rights Reserved.
Talk-Thru™ is a registered trademark of Norcon Communications Inc.
Due to continuous product improvement, all colors, sizes, materials, finishes and specifications are subject to change without notice.