MH/T 4002.1-2015 in English

Background of Standard Evolution

MH/T 4002.1-2015 replaces the 1995 version of the standard and achieves three major technical upgrades: system architecture expansion (new monitoring/transmission modules), parameter system improvement (adding 12 indicators such as PEP power/ALC characteristics), and test method standardization (new Appendix A normative test process). Compared with the old version, the main changes are as follows:

Core technical requirements

System architecture

It consists of 8 major modules, including shortwave transmitter, receiver, antenna system, etc. Key features:

• All-solid-state circuit design: 100% DSP and frequency synthesis technology required
• Dual-mode monitoring interface: Supports both RS232 and Ethernet protocols
• Intelligent protection mechanism: VSWR abnormality/overcurrent/overvoltage triple protection

Key performance indicators

Key points for implementation

Site construction specifications

According to the Fresnel zone calculation formula in Appendix B: When the antenna height is 10m, the radiation elevation angle of 10° needs to ensure a 200m diameter barrier-free zone (compromise solution). Special requirements include:

• The elevation angle of obstacles in the transmission direction ≤ 1/4 of the main lobe elevation angle
• Normal operation must be ensured below 3000m above sea level
• Maintain a distance of more than 500m from roads/industrial facilities

Maintenance recommendations

Focus on monitoring the VSWR of the antenna tuner (should be ≤2:1), regularly verify the ALC characteristics (power fluctuation <1dB when input -20~+10dBm), and establish a reliability file with MTBF≥5250h.