HCD28 (8)/TSD Low Radiation Phone is a government exclusive telephone designed for simplicity and practicality, commonly used as a wired communication terminal. It is primarily for military and local government party and political networks. Suitable for programmable, automatic, and common battery telephone exchanges, it features excellent voice transmission quality, high reliability, lightning protection, and low electromagnetic leakage.
Features：
Key Features
Compliant with FSK/DTMF dual-mode caller ID standards.
Live call and outgoing call dynamic storage, incoming calls up to 8 digits with a maximum of 80 groups, outgoing calls up to 12 digits with a maximum of 15 groups.
Two sets of 32-bit direct storage memory.
Voice-number announcement
5 original songs performed by real singers, 8 high-fidelity chord ringtones, 3 special sound effect ringtones, and 8 standard ringtones.
5-digit area code, 2-digit exit code
32-bit dialing pre-emption and error correction
Call forwarding and return call;
Automatic Call Forwarding Feature: hands-free volume adjustment;
Ring volume adjustment
Music play function
Date, clock, and call timer functions;
LCD brightness with 5-level adjustment, intelligent backlight;
Redial the last 32-digit number.
Number issuance pause feature
Faster Disconnection Feature
Keyboard backlight.
Key Performance Indicators (KPIs)
Terms of Use
Ambient Temperature: -10℃ to 40℃
Relative Humidity: 10% - 95%
Atmospheric Pressure: 86kPa ~ 106kPa
Ambient Noise: ≤60dB(A)
Key Technical Parameters
Electroacoustic Parameters (5km): Sound Level Rating (SLR) ≤ 15 dB
Received Loudness Rating (RLR) ≤ 2 dB
Side Tone Masking Rating (STMR) ≥ 12 dB
Stable Balance Return Loss (2km): ≥15 dB
Echo Balance Return Loss (2km): ≥17 dB
Transmission and reception of non-linear distortion: ≤7%
Direct Current Resistance: ≤350Ω
Ringing Level: High Gear ≥ 70dB(A), Low Gear < 67dB(A)
Wiring resistance: ≤350Ω
Dual-Tone Multi-Frequency (DTMF) Signal Level: Low Frequency Component -9dBm ±3dB
High-frequency Power Level -7dBm±3dB
The high-frequency component level is 2dB ± 1dB higher than the low-frequency component level.
Mean Time Between Failures (MTBF): ≥5000h
Power Source: 3 AA batteries
Dimensions: 266mm x 200mm x 82mm
