Vacuum Tubes at EPO!

At EPO we have a wide variety of vacuum tubes which you can mainly use in vintage radio equipment, guitar amplifiers, among others. We also have available a tube tester for costumer use with instructions, so if you have tubes that you would like to test, you can do it here at Electronic Parts Outlet - Houston.

For more information, please call us or, preferably, come and visit us at Electronic Parts Outlet - Houston where you will find all kinds of things that will be useful for future projects.

This is just an example of the tubes we have with different part numbers; frequently these last ones change and this table is modified through the tubes that were tested and we are selling at that particular time.

For more information, please call us or, preferably, come and visit us at Electronic Parts Outlet - Houston.

 

TUBE TESTER AT EPO

Our tube tester works in the following way:

  1. Locate tube type on chart and set SELECTOR knobs -A-, -B- and -C- to chart readings. Net, insert tube in socket indicated on chart and allow 20 seconds for warm-up.
  2. If either TUBE SHORT light on meter glows when TEST knob is in SHORTS or GAS position, tube is DEFECTIVE and should be REPLACED, regardless of meter Value Number reading.

 

 

HOW OUR TUBES ARE GRADED

The vacuum tubes you see here were tested using two different tube testers to measure emission, check for short circuits, and intermittent behavior. One type tester is known as a static emission test that also checks for internal short circuits and intermittent operation under load. The other tube tester is called a mutual conductance tester and puts the tube in an actual amplifier type test mode and tests for shorts and emissions.

By comparison, Both testers; With very different read outs, agree about 95% of the time in determining the merit or strength of the tube being tested. The emission tester has a meter scale that goes from 0 to 100. The mid range is shown to be 50, and a tube under test must show 50 or higher on the meter in order to pass. The mutual conductance tester operates from a scale of 0 to about 120. A tube is assigned a minimum value along that scale for pass/fail criteria.