Walker PTT-K-M-EM-80-RP-00 Push-To-Talk Reverse Polarity Telephone Handset

Walker PTT‑K‑M‑EM‑80‑RP‑00 – Reverse Polarity Push‑To‑Talk Handset for Nortel Meridian Systems

The Walker PTT‑K‑M‑EM‑80‑RP‑00 is a specialized push‑to‑talk (PTT) handset designed for use with Nortel Meridian phone systems (e.g., Meridian 1, SL‑1, Norstar) that require reverse polarity wiring. Unlike standard PTT handsets, this model has its audio and PTT contacts reversed to match the specific pinout of Meridian consoles and adapters. Built for heavy use in security dispatch, emergency response centers, and industrial control rooms, this handset features a large, glove‑friendly PTT button, a noise‑canceling microphone, and a rugged, impact‑resistant housing. The reverse polarity configuration ensures plug‑and‑play compatibility with Meridian equipment that expects this wiring scheme – no custom adapters or rewiring needed.

How It Works

The handset connects to a compatible Nortel Meridian console, paging adapter, or telephone system using the included modular cord (RJ12 or RJ45, depending on the adapter). The “reverse polarity” means that the tip and ring wires for the microphone and speaker are swapped compared to a standard telephone handset, while the PTT switch contacts are also reversed. When the user presses the large PTT button, the handset transmits the microphone signal to the system; releasing the button returns it to listen mode. The noise‑canceling electret microphone reduces background noise, and the dynamic receiver provides clear audio. The handset is designed for half‑duplex PTT operation, typical of dispatch and security networks. For a complete communication hub, pair this handset with a reliable corded headset from FindHeadsets – ideal for staff who need to monitor multiple channels while keeping their hands free.

Compatibility & Design

The PTT‑K‑M‑EM‑80‑RP‑00 is specifically designed for Nortel Meridian 1, Meridian SL‑1, Norstar, and other Meridian PBX systems that use a reverse polarity PTT handset interface. It is a direct replacement for legacy handsets on Meridian consoles, operator positions, and paging adapters. The handset is constructed from high‑impact, flame‑retardant ABS plastic with a reinforced, kink‑resistant coiled cord (approx. 2.5m retracted, extending >6m). The PTT button is large, tactile, and rated for thousands of cycles. The microphone is noise‑canceling, and the receiver is amplified for clarity. The handset includes a hook switch for cradle operation. It operates from -20°C to 60°C and is IP54 rated for dust and splash resistance. The black finish is scuff‑resistant. Wiring is reverse polarity as specified; please verify that your equipment expects this configuration.

Why Choose This Product

Using a standard PTT handset on a reverse polarity Meridian system will not work correctly – you’ll get no audio, or the PTT button may not function. This handset is purpose‑built with the correct wiring, saving you time and troubleshooting. The rugged construction outlasts consumer‑grade handsets, reducing replacement costs in demanding environments. The noise‑canceling microphone is critical for dispatch centers where background chatter is common. The long, reinforced cord allows operators to move while talking. For facility managers, this handset is a direct drop‑in replacement for worn or damaged Meridian PTT units, with no special adapters required.