Converting ac to dc has been accomplished by several different types of rectifiers through the years. Here are a few of the more common types of rectifiers used in the past 100 years. Mercury arc ...

Even if you aren’t a tube aficionado, you can’t help but be mesmerized by the blue glow inside a mercury vapor rectifier when it operates. It looks less like early 20th century tech and more like ...

Single-ended tube with a brass admedium base insulated skirt and two glass insulators. Tipless T-shaped envelope. 1 amp rating. Donor’s card reads: “Tungar rectifier bulb made by the General Electric ...

Even if you aren’t a tube aficionado, you can’t help but be mesmerized by the blue glow inside a mercury vapor rectifier when it operates. It looks less like early 20th century tech and more like ...

A 4-pin brass base with ceramic insulator, two parallel elements mounted vertically, tipless S-shaped envelope. Printing on base mostly indistinct: "U ...

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 ...