[Hallicrafters] The 8122, 6146, 6HF5, and 6KD6 Enigma

[Jim Liles]

The following information will help to understand why vacuum tubes behave as they do.  We focus on the 8122 used in Class AB1 service as well as just about any tube used under Class parameters.  What you’ll find is tubes like the 6146, 6HF5, 6KD6, and others have the same frailties and strengths as the 8122.

If you are restoring or servicing any vintage transmitter or transceiver you will find the following link to be interesting and it will save you a good deal of grief.  If nothing else, it will help to understand the idiosyncrasy's and some times bizarre behavior of these tubes and how to cope with them.   

http://k9axn.com/_mgxroot/page_10868.html

If it is unclear please send a note so we can correct the language.

Kindest regards Jim K9AXN