Part 3 of the "Vacuum Tube Tester" - Series. <br />This time I perform some experiments to demonstrate the Edison / Edison-Guthrie-Effect (aka. as "Thermionic Emission"), on which vacuum tubes are based. I also show some methods to re-purpose magnetic moving coil instruments.<br />Support my channel: <br /><br />Patreon: <br /><br /><a href="https://www.patreon.com/TPAI" target="_blank" rel="nofollow">https://www.patreon.com/TPAI</a><br /><br />Paypal:<br /><br /><a href="https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=inventordonations%40gmail%2ecom&lc=US&item_name=The%20Post%20Apocalyptic%20Inventor&no_note=0&currency_code=USD&bn=PP-DonationsBF%3abtn_donateCC_LG%2egif%3aNonHostedGuest" target="_blank" rel="nofollow">https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=inventordonations%40gmail%2ecom&lc=US&item_name=The%20Post%20Apocalyptic%20Inventor&no_note=0&currency_code=USD&bn=PP-DonationsBF%3abtn_donateCC_LG%2egif%3aNonHostedGuest</a><br />...<br /><a href="https://www.youtube.com/watch?v=LPzTdp64PWc" target="_blank" rel="nofollow">https://www.youtube.com/watch?v=LPzTdp64PWc</a>