ARRL The Doctor is In
///////////////////////////////////////////
Vacuum Tubes
Posted: 14 Feb 2018 09:15 PM PST
https://www.blubrry.com/arrl_the_doc.../vacuum-tubes/
These classic devices are not as common as they used to be, but they are
far from extinct.
This posting includes a media file:
http://media.blubrry.com/arrl_the_do...ry_15_2018.mp3