Description

Three tubes that have been marked with their calibration values to be used in calibrating the TV-7 series tube testers. These have been calibrated using a known good tester serviced by a professional. Included are all three types of tubes needed to test all the ranges on a TV-7. Some people refer to these as "bogie tubes". These tubes will also be marked in their umhos value. THIS SET IS IDENTICAL TO MY OTHER TV-7 CALIBRATION TUBE SET EXCEPT THAT THESE ARE ALSO MARKED IN UMHOS. It takes about 40 additional minutes to mark these properly with umhos thus the higher price. NOTE: This combo offering may take up to a week to ship as I have to hand make these and don't keep them in stock. Tube may be used (which is actually a good thing for calibration tubes). Tube in picture are just representative, not the actual tube you will receive. We use brand name tubes such as RCA, Sylvania, Tung-Sol, etc. for making these sets. These tubes are tested for shorts / gas before calibration. We offer instructions on our website on how to calibrate the TV-7 series: https://blueglowelectronics.wordpress.com/tv7/ We have also made a 1.5 hour video on the process to help aide you. https://youtu.be/Ru-AR9HTqgc Note: on the 12AT7, we only mark one side of the tube. I have found in marking both sides, it confuses some newer techs thinking they need to calibration two "circuits" in the tester to "calibrate" both sides, when in reality, the only difference between one side or the other is the tube pinout selections via the knob settings. There is only one calibration for range C, which this tube is used for. We offer no guarantee that these instructions alone will make you successful, you must have a good understanding of vacuum tube electronics to consider calibrating one of these units. This auction is just for a set of calibration tubes needed to complete the process. If you don't have the background or skills, please seek out professional help. Tube Tester NOT Included