About my tunnel diode blog - I am suing the free Google blog service called "Blogger". You can see that I have a couple of other old, out of dated Blogger blogs, mainly on Rpi experiments. These couple of years I am using rpi.org/blog. It is good for projects: Relay Module KY-019 5V - tlfong01, www.raspberrypi.org/forums/projects/automation,sensing, and robotics
https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=77158#p1323061. The good thing of this kind of project blogs is (1) You can start a project, or just exploring something, say, I did not know anything about relay, so I joi…