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 ...

Raytheon is best known as a major defense contractor, but the company’s roots go far deeper, starting as a major manufacturer of vacuum tubes in the early days of radio. Today, the company is mostly ...

[Eric] has an Atwater Kent 55C AM radio from the early 1900’s. He’s been trying to restore the radio to proper working condition. His most recent pain has been with the rectifier tube. The tube is ...

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 ...

WHEN an alternating current arc is established in a vacuum tube between a mercury and an iron or graphite electrode, the current only passes during half the time, namely, when the mercury pool is the ...

An 8-pin base with center post, metal shell, and glass insulator. T-shaped envelope. Stamped: "35Z3". Philco stamp on envelope under masking tape. Donor’s card reads: “Half wave high vacuum rectifier ...

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