John Dunn recalls a close call with at at-home vacuum tube experiment and shudders at the thought of using another particular ...

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 ...

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 ...