Stop staring at that old television and start watching it again with an RCA 35W4 Vintage Tube and Tube Socket. Produced by RCA circa 1945, this stock vacuum tube still has what it takes to keep electronics running for years. These 35W4 vacuum tubes have a seven-pin configuration. The pins reach out of the bottom of the 2.0-inch long chassis. The diameter of these 35W4 tubes is about 0.9 inches. The exterior of the tube features the familiar RCA logo and the date of the product's production. Vacuum tubes such as this are used in home-built audio equipment like amplifiers and pre-amps.These miniature seven pin tubes function as a rectifier. When installed into a piece of electrical equipment, they function as a hot chassis and series-wired heaters. The lamp portion glows and heats, allowing for an instant-on to the power supply of the television set or amp.This rectifier can deliver alternating current (AC) or battery-driven direct current (DC) to your device. When it switches direction, it enters the rectification process. This process is desirable when you need a dependable direct current power supply. They will conserve electricity and deliver consistently timed and sized pulses of current. The steady direct current is managed by an electronic filter that modulates the electrical flow. The filters function as capacitors and produce the steady flow of electricity that TVs, radios, and amps need while in constant use.The circuit of this 35W4 rectifier is designed as a diode. A diode includes a copper oxide filament connected to the cathode. As a single-phase unit, the 35W4 eliminates harmonics for the delivery of crisp audio. These tubes deliver a frequency response of 10 to 20,000 KHz.While this vintage tube was originally created for delivering voltage to TV sets, it is also ideal for providing ample voltage to radio and musical amplifiers. If your equipment needs a replacement tube, this plate glass RCA model is ready to get you up and running. Whether you miss an older TV set or want to see how far your ham radio can reach, the RCA 35W4 is standing by. It features a black plate that is specifically designed to resist vibration. This allows the tube to enhance electron flow toward the cathode. These units are also designed to receive amplitude modulation (AM) broadcasts in the medium radio frequency wave band.You can install these heater tubes into an amplifier or guitar amp in series or in parallel. They can also be installed as a matched pair as replacement products for vintage units. They provide your antique radio or amp with a 120-volt main supply. The 120 volts of output is sufficient for most modern amps and equipment. These 35W4 radio tubes are designed to be installed in a specific configuration for the minimization of harmonic distortion. The heater string of these tubes in an AC/DC radio also allows for the elimination of humming. This ensures that all you hear is the music and vocals of a song. The optimal location for these tubes is placed between a resistor and an audio power output amplifier.