Cristiano Maker

 Today, I made a simple video demonstrating how the control grid of a vacuum tube triode may work. Essentially, the purpose of a control grid, is to control the flow of electrons from the cathode to the anode of a vacuum tube. So, im my experiment, I put my ammeter in series with the B+ and the tube plate and applied a positive charge from a 9v battery and then I inverted the battery polarity, applying a negative charge. In the first case, It is possible to see the current flow increasing, while in the second case, the current practically doesn't flow anymore. You can see this simple experiment in the YouTube video below: For this experiment I used an early type 30 tube, a 1.5v battery and a 90v stack of 10 * 9v batteries and a couple of wires. Hope you like!

 I live in an old house that has no grounding system. As I do many projects using considerable voltages, like vacuum tube amplifiers, I need at least a grounded wall socket for my own security and the security of my devices. So, as my house is rented, I don't want to request someone to make a full/proper ground installation for the entire house. Instead, I created my own grounded socket. Fortunately, the house as a backyard, so I bought a copper grounding rod and buried it into the backyard and then I took a thick wire from it to the inside of the house and made a connection to the ground pin of a "female" socket and I'm using it for my projects. Below, there is a simple video showing the efficiency of that system I made: You you have a similar situation as mine, you can do something similar.