HCD28P/TSD Low Radiation TelephoneA simple and practical government-specific telephone, commonly used as a wired communication terminal. Mainly used for equipping military and local party and government special networks. Suitable for programmed, automatic, and common battery telephone exchanges, featuring good voice transmission quality, high reliability, lightning protection, and low electromagnetic leakage.
Feature Highlights：
Primary Functions
Compatible with FSK/DTMF call display standards.
Phone Calls: Up to 16 groups of 8 digits, dynamically stored internally, with a maximum of 32 digits.
Call: Up to 52 groups of 8 digits, with full dynamic storage for single key and automatic IP.
Three sets of 32-bit direct storage memory
Intelligent Backlight
Callers can be set as VIP with anti-deletion protection, and special ringtone for incoming calls.
24 diverse ringtones available, with customizable ringtone sizes.
5-digit area code, 1-digit outgoing code, incoming call filter
32-bit pre-dialing and error correction
Call forwarding and return call;
Automatic Call Back Feature
Hands-free volume control adjustment
Music play function;
Phone numbers can be saved to the direct storage memory.
Date, clock, and call timer functions;
LCD Brightness Adjustment
Redial the last 32-digit number.
Feature to pause number issuance
Interruption function.
Key Performance Indicators (KPIs)
Terms of Use
Ambient Temperature: -10℃ to 40℃
Relative Humidity: 10% ~ 95%
Atmospheric Pressure: 86kPa ~ 106kPa
Ambient Noise: ≤60 dB(A)
Key Technical Parameters
Electro-acoustic Parameters (5km): Sound Level Rating (SLR) ≤ 15 dB
Receive Loudness Rating (RLR) ≤ 2 dB
Side Tone Masking Rating (STMR) ≥ 12 dB
Stable Return Loss (2km): ≥15dB
Echo Balance Return Loss (2km): ≥17dB
Transmission and reception of non-linear distortion: ≤7%
Direct Current Resistance: ≤350Ω
Ringing Sound Level: ≥70dB(A)
Wiring Resistance: ≤350Ω
Dual Tone Multi-Frequency Signal Level: Low Frequency Component -9dBm ±3dB
High-frequency Components -7dBm±3dB
The high-frequency component level is 2dB ± 1dB higher than the low-frequency component level.
Receive incoming caller ID FSK signal:
"0" = 2200 Hz ± 1% Level: -37 dBm to -6 dBm
"1" = 1200 Hz ± 1% with a level of -32 dBm to -6 dBm
Level Difference: ±10dB
Average Mean Time Between Failures (MTBF): ≥5000h
Power Source: 3 AA Batteries
Dimensions: 228mm x 180mm x 105mm
