THE student with a good knowledge of general physics will find this volume very helpful in studying radio-frequency phenomena. Modern thermionic tubes have so many important applications in physics ...

Older table-top AC-DC radios used a classic line-up of tubes. Think 12SA7, 12SK7,12SQ7, 35Z5GT, and 50L6GT. As I grew into my teens, I got interested in how these radios worked and soon discovered ...

Variable capacitors may be useful, but the air gap that provides their capacitance is their greatest weakness. Rather than deal with the poor dielectric properties of air, some high-end variable ...

If you'd rather not be tethered by a power cord while cleaning, the best cordless vacuums deliver top-tier suction power and cord-free convenience. Cordless stick vacuums are also lightweight and easy ...

Vacuum therapy is a noninvasive method that temporarily improves the appearance of cellulite. The effects of vacuum therapy are not permanent and may need repeating after one month. Vacuum therapy is ...