How do you read a vacuum tube number?

CV numbers Format is CV followed by up to 5 digits, e.g. CV4004. Used by the British Military to codify vacuum tubes, gas tubes, and latterly, some semiconductor devices. CV numbers can be directly mapped onto NATO numbers, as 5960-XX-000-YYYY where XX is the country code, and YYYY is the CV number.

Which vacuum tubes are valuable?

Here is a shortlist of valuable vacuum tubes for collectors:The 2A3 (from $50), 45 (from $25), 50 (from $200) are enjoyed explicitly by the audiophile crowd.The 12AX7 preamp tube (from $10)The American 6L6 tube (from $15)15 Aug 2021

How can you tell a 12AX7 tube?

They can be identified by the Gold Mullard 10M Logo on the tube and they have gold or regular pins. The Gold Pin versions are superior and worth more. These tubes are highly sought after by audiophiles. They have a wide-band sound similar to a Telefunken, but with a touch of that Mullard warmth.

Who made national union tubes?

In 1981 the National Union ELectric Corp was still a subsidiary of Electrolux. NU made receiving tubes up into the late 1950s, and continued to make odd special purpose types up to at least 1968, when they registered their last type (type 8632).

When should vacuum tubes be replaced?

4:075:49When should you change vacuum tubes? - YouTubeYouTube

How many hours do vacuum tubes last?

Depending on how often you turn on and turn off your gear, but tubes should last about 5,000 to 10,000 hours. For most people, they only need to be replaced every 2-3 years at most. But its good to have at least a spare set around just in case one of them decides to die on you.

Are old vacuum tubes worth money?

Some older Western Electric tubes unused or the original box will sometimes sell for over a thousand dollars at auction. Any early vacuum tube with a “tip” (the little glass nub on the top) and a brass base has some value to collectors even if its just usable for display.

How do you date GE tubes?

There are two sorts of date codes on GE tubes. One is the printed date code and one is the sand-blasted dot code. As far as the printed date code goes, from 1948 to 1955 it has a Y-MM pattern. From 1956 to 1964 it was a YY-MM pattern.

What do vacuum tube numbers mean?

1. What do the numbers and letters in a tubes name mean? There are several different tube numbering systems that you may see on tubes, which generally are a result of where they were built. Most commonly the numbers contain digits only (e.g. 5751), or are some combination of numbers and letters (12AX7, ECC83, CV4004).

How do I know if my tubes are bad?

Sometimes you will hear strange sounds, loss of power, or heavily distort sound. These are signs that a tube is failing. Often power loss that seems like the amp is performing at half power or less will be one or more bad power tubes, or even a dying phase inverter tube.

When did they stop putting tubes in radios?

All radios produced during the first half of the 20th century were tube radios, since transistors were not invented until 1947 and did not start to replace tubes in radios until 1954.

What are the tubes in old radios called?

The vacuum tube is then known as a triode, tetrode, pentode, etc., depending on the number of grids. A triode has three electrodes: the anode, cathode, and one grid, and so on.

How do you know if a vacuum tube is bad?

When a vacuum tube develops an air leak (a small crack or bad seal by a pin for example) this getter color will change to pure white. If you see this you know with 100% certainty that the tube is bad. Third, look for a purple glow that is very focused around specific elements inside the tube.

What happens if a vacuum tube breaks?

Myth 3: Vacuum tubes explode when broken. If broken, a vacuum tube implodes,due to the negative pressure of the vacuum. This means the glass stays put, posing no projectile hazard.