Vacuum Tube Testers
If you're working with any kind of vacuum tube assembly, then you'll need to have a tube tester on hand to make sure that all of your valves are working properly. Tubes should be tested in everything from vintage radios to contemporary guitar amplifiers, and it’s easy to put all of your valves through a tube checker.
How do tube testers work?There are several different types of testers on the market. Filament continuity testers put a voltage across the terminals of tube sockets to test whether or not they work. An emission tester is a bit more sophisticated. This testing treats all tubes as diodes. They connect the cathodes to ground terminals and then grid the plates to a known value of B+ voltage. This helps the tester automatically tell if the tube is good. Dynamic conductance testers use proportional AC voltages instead of standard plate currents.
Do electron tubes and tube testers give off radiation?The emission levels of ionizing radio are quite low in a majority of vacuum tubes. Good tube tester units don't give off any measurable quantity of radiation at all. Large cathode devices used inside of CRT displays do contain a radioisotope, but the tube tester you would use for these displays is not itself radioactive.
How are the Hickok 539B and 539C tube testers different?Hickok made and sold 3 different types of transconductance tube testers under the 539 brand. The B and C types have a few more additional features than does the A type. The Hickok 539B is known as the engineer's model because it measures true transconductance in micromho units. Other Hickok testers feature a different type of scale. This model features a separate line of voltage meters to keep the tester properly adjusted. It originally also came with a calibration manual and a set of octal and acorn sockets.
How does the Mullard–Philips tube designation work?If you have a thermionic valve tube tester from Europe, then you'll find that the electron tubes it works with follow a rigid naming pattern called the Mullard-Philips designation. All electron tubes have names that start with a letter and then feature a number of symbols after that. These symbols represent the following values:
- Initial letter - heater rating
- Following letters - type of device assembly
- Following number - base type
- Final digits - manufacturer's serial number
- Optional single digit - designates a foreign base type