Here is a letter from the Technical Service department of CBS Hytron tube company, dated June 1954, that discusses a common problem with tube testers. In this letter [ PDF ], which I scanned and restored via Photoshop for better readability, a person from the Max Fischman Co of Pittsburgh wrote to CBS Hytron Co. […]
CBS Hytron 12BH7 letter about Hickok test Read More »
Meter reading Range Micromhos BCDEF Reset DIRECTIONS: Enter your meter reading (0 – 120) into the “Meter reading” box. Choose your Range Switch position in the drop-down box. Press the “Calc Gm” button and read your micromhos score. Press “Reset” button to clear your entries or to start another calculation. NOTES: calculator works for all
TV-7 micromhos conversion calculator Read More »
“Standard Brand“, “Rad-Tel“, “Atomic“, “Cosmic” — what kind of brands are these? I found an interesting tube-related article in the Dec-1955-Jan-1956 issue of NATIONAL RADIO-TV NEWS. The article exposed a supply-chain problem during the 1950s where unscrupulous vendors would buy “pull-outs” (duds or near-end-of-life tubes) from repair shops, then manipulate the tubes in a manner
the Reprocessed Tube Racket Read More »
©2011 Bob Putnak. I am frequently asked how to test voltage regulator (VR) tubes, which are sometimes called “glow regulator” or “glow discharge” tubes. Few tube testers test VR tubes, and most models that claim to test VR tubes do a worthless job at this task. They use AC voltages instead of DC the AC
Testing Voltage Regulator (VR) tubes Read More »
Here is something that you will not see everyday, an NOS NIB NEW Globe-style Arcturus blue-glass 071A audio output tube. Type 071A is also known as 71-A, 71A, 171A, 271A, 371A. This tube has the star-logo on the top of the glass bulb with 071A inside the star logo. Engraved base reads “ARCTURUS – No.
NOS NIB NEW Arcturus Blue 071A tube (71-A) Read More »
