A kind of 1960-70s Japan's industrial high school education (in Japanese)

This is an experiment 455kHz IF injection to the antenna wire of heterodyne radio, which we senior Japanese learned during the age of 16-18 in vocational education. As no video recorder at that time, I re-constructed this from my memory. Perhaps some schools had used transistor circuits in the class already, I prefer to use Tube radios to show the result this time. Those days many high skilled young workers learned these difficulties graduated K12, then became the basic manpower for the rapid economic growing in Syowa era of Japan. I wonder how many K12 graduators now can understand this kind of practical education ... for Japanese high school is too much paper test oriented, not aiming practical skill or technological development, the goal is simply to pass the entrance examination to University and after that nothing. This video content have already been outdated that I know but I'm sure it's still important to develop the skill to analyze electric circuits or solve logical problems.

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