TDA2009 power amplifier circuit

Power amplifier circuit diagram

Radio direction finding and PJ-80 type direction finding machine circuit

Speaker indicators

5.1 channel speaker technology

Transistor low frequency amplifier

[Photo] Design and Analysis of Spike Cayin230C Combined Transistor Amplifier

144MHZ nine section Yagi antenna

Analysis of basic terms of sound card

[Photo] Audio transponder without battery

Two-meter, two-watt FM phase-locked transmitter

Beijing FM Radio Frequency Table