9‑Person Simultaneous Calling: Alinco Introduces DJ‑R531 DECT Wireless System

Supports Simultaneous Calls for Up to 9 People — Alinco Launches 1.9GHz DECT-Based Wireless Communication System for On‑Site Operations: DJ‑R531P / DJ‑R531

Alinco Co., Ltd. announced on April 1, 2026, a dedicated wireless communication system for use during work operations. The system consists of the DJ‑R531P base station and DJ‑R531 handset, the company’s first products using 1.9GHz DECT (Digital Enhanced Cordless Telecommunications) technology. It enables simultaneous voice communication for up to nine users without requiring an audio mixer, and delivers clear audio through high‑quality noise reduction. The system requires no operating license, with a communication range of approximately 300 meters over flat, unobstructed terrain and around 100 meters in urban areas. Pricing is yet to be determined.

Alinco’s DECT‑based on‑site communication wireless system. The base unit (DJ‑R531P) is silver, and the handset (DJ‑R531) is black. The chassis is constructed from polycarbonate.

DECT（Digital Enhanced Cordless Telecommunications）is an international standard for digital cordless telephones operating in the 1.9GHz band, using TDMA‑WB (Time Division Multiple Access Wide Band) 。as its communication method. Japan’s Ministry of Internal Affairs and Communications has published technical standards for DECT, with implementation starting in 2011. It is now widely used in digital cordless phones, wireless doorbells, wireless transceivers, communication headsets, and home security devices.

The Alinco DJ‑R531P / DJ‑R531 operates within the DECT allocated frequency band of 1885.248–1904.256MHz. It uses TDMA digital GMSK modulation with a transmit power output of 0.1W. The company states: “No license, qualification, or application is required whatsoever, nor are there any call or radio usage fees. Anyone may use it for any purpose.”

The following is an excerpt from Alinco’s official announcement:

A transceiver supporting simultaneous calls for up to 9 people via 1.9GHz DECT!

Alinco Co., Ltd. is releasing the “DJ‑R531P / DJ‑R531”, a simultaneous communication system utilizing 1.9GHz digital band technology. Unlike conventional simultaneous communication systems, this product adopts 1.9GHz DECT technology, enabling simultaneous calls for up to nine users without the audio mixer typically required for on‑site wireless communication equipment. It also provides clear call quality through high‑definition noise reduction.

Key Specifications

★Dimensions: 56.5mm (W) × 94.7mm (H) × 28.7mm (D) (excluding protrusions) Weight: Approx. 184g with EBP‑114 battery pack; approx. 220g with EDH‑46 battery case (including 3 AA batteries)

★Simple operation: After registering handsets to the base unit once, users can start talking by pressing the PTT key upon power‑on. Handsets can freely join or leave the communication group until the base unit is powered off.

★Color-coded design: Silver base unit, black handsets for easy identification. Rugged polycarbonate housing with IP67 dustproof and waterproof rating.

★Built-in Bluetooth module: Compatible with the EME‑80BMA wireless headset and supports control of commercially available headsets via the onboard PTT key.

★High-capacity 3120mAh lithium‑ion battery pack providing up to approx. 19 hours of operation; approx. 15 hours using 3 AA alkaline batteries in the optional battery case, ensuring ample talk time.

★Five EDC-331R charging cradles can be connected in series and powered by the EDC-162 AC adapter. A second set of four linked cradles allows simultaneous charging of up to nine devices. For individual charging at separate locations, the single‑unit EDC‑331A charger set is available.

★TDMA digital GMSK modulation for clear, noise‑free audio.

★One-touch transmit hold function: remains in hands‑free PTT transmit mode until pressed again.

★Digital noise reduction processing on the transmit microphone to deliver clear audio to the receiving end.

★Sidetone monitoring (echo monitoring) to confirm one’s own transmitted voice.

★Standard features including wired headset/microphone disconnection detection.

Optional five‑unit linked charger consisting of individual battery‑charging EDC‑331R cradles and EDC‑162 adapter.

Rated Specifications

Transmit/receive frequency: 1885.248MHz – 1904.256MHz

Modulation types: F1D, F1E, G1D, G1E

Transmit power: 0.1W

Receive sensitivity: –93dBm (BER 1%)

Audio output: 80mW or more (8Ω load)

Power supply voltage:

Lithium‑ion battery: 3.6V / 3120mAh (EBP‑114, sold separately)

AA alkaline batteries: 4.5V (EDH‑46, sold separately)

Current consumption: 150mA or less

Operating temperature range: –10°C to +50°C (charging: +10°C to +40°C)

Dimensions (excluding protrusions): 56.5mm (W) × 94.7mm (H) × 28.7mm (D)

Weight:

Approx. 184g (with EBP‑114)

Approx. 220g (with EDH‑46, including AA alkaline batteries)

Operating Time Reference

Lithium‑ion battery: Approx. 19 hours

AA alkaline batteries: Approx. 15 hours

DJ‑R531 Side and Rear Views

Communication Range Reference (between base unit and handset)

Flat unobstructed areas such as riverbeds: Approx. 300 meters

Urban areas: Approx. 100 meters

Areas with few tall buildings or obstructions: Approx. 150 meters

Inside buildings: Varies significantly depending on structure, building materials, and partition arrangements.

Notes on 1.9GHz DECT Simultaneous Communication

The DJR531 system does not use the manual channel selection found in conventional radio equipment. After a onetime registration, the base unit automatically detects and connects to handsets at poweron. The system automatically selects an available frequency, preventing signal interference and eavesdropping.

·  To use multiple communication groups, perform initial registration of base units and handsets separately for each group. Operation within the coverage area of another group may cause accidental crossregistration. If misconfiguration occurs, reset the units and restart the setup process.

·  Like digital cordless phones, calls cannot be eavesdropped on by third parties after initial registration. However, while the system uses lowpower signals with a limited interceptable range, handsets registered by other users may monitor calls during initial registration. For example, if only six handsets can be registered when up to eight are supported, at least two handsets have been incorrectly registered.

·  Thanks to digital technology, audio remains clear within communication range, but calls will cut off immediately if signal strength weakens. Communication resumes automatically when moving closer to restore signal strength.

·  Registration may take up to approximately 15 seconds. If power is interrupted during registration, replace or recharge the battery and restart the process.

·  Similar to how Bluetooth wireless headsets may experience audio dropouts in crowded trains, this system may suffer call interruptions in areas densely populated with other 1.9GHz band devices.