This paper analyzes the explosive welding in hemispherical resistance wave instrument,explosive blasting,shock waves propagation,and shock waves reflection are simulated for TNT and ANFO respectively.

This paper utilized a new brand filter-a hemisphere filter-in the research of anti-aliasing.

Discussion on test of line trap and combined filter;

A special fault analysis and solution of carrier high frequency line trap;

The analysis of self resonance over voltage on line trap at short time current test;

Simple methods in wave trapper inspection;

Through investigation of a protection misoperation caused by wave trapper damage,the transmission principle of high frequency current signals in HF channel was introduced and wave trapper input impedance characteristics test were presented.