Active and passive speakers

The post-stage part of the electronic frequency divider before and after the amplifier (3)

High-fidelity audio power amplifier TDA2040

Microwave induction control circuit

How to start the "drive unit" of speaker design

[Photo] Talking about the production and debugging of FM transmitter

Procurement principles of multi-channel speakers

Suitable for homemade small antenna

My GP antenna

[Photo] Dolby B noise reduction IC NJM2063A

Interphone Knowledge Collection

800-meter transmitting circuit using acoustic meter resonator