Metal detector update (VLOG) and schematic & demo of a useful 2 transistor audio beeper (1970's) скачать в хорошем качестве

Metal detector update (VLOG) and schematic & demo of a useful 2 transistor audio beeper (1970's)

Please read the description first, for the best and most complete information. Update on the earlier metal detector circuit, that was ( 1 february 2026) here    • Metal detector circuit 3 transistors. Say ...   I now (8 feb. 2026) used another type of oscillator, but I don’t want to publish it all on YouTube, before it is properly tested, by detecting metal things (steel etc.) immersed in dry or wet soil. More explanation about that is in the video now (8-2-2026). At the moment the metal detection only works in a dry environment. Say on my workbench or in a household. It detects steel things at distances of 20 cm. Important: thus a new type of 1 transistor oscillator is used in this experiment, and it is set to “hick”, by connecting a 2.2 uF electrolytic capacitor to the input of the 3 transistor amplifier. The 3 transistor amplifier (4 feb. 2026) is here:    • 3 transistor mini amplifier for 9 Volt onl...   That “hicking” to the 3 transistor amplifier makes the detection coil more sensitive. Compare it (in a certain way) to the so called “superreg” principle, where the transistor that receives radio signals on the antenna is set to “hick” on frequencies in the Shortwave frequency range, say by switching it “on” and “of” on (say) 22 KC - 40 KC or so frequency. It makes the radio (on its antenna) very sensitive. More info about that principle (supperreg) is on the www. NB: the circuit now is not complete “superregging” (….). About the very easy to make 2 transistor beeper circuit (audio range 300 Hz up to say 18 KC) everything is showed and told in the video. Change the 0.1 uF capacitor to other values, in the range (say) of 1 uF to (say) 4700 pF and turn the 100 K bias potentiometer to get idea’s about the good properties of this 1970s circuit. My You Tube channel trailer is here:    • Radiofun232 on YouTube, find working & tes...   Interested in certain electronic circuits? (Radio’s, audio amplifiers, audio pre-amps, audio filters, measuring devices to test transistors and (say) mosfets or (radio) coils or Shortwave and MW radio’s? Go to my Channel Trailer (“Radiofun232 on YouTube”). Type there the keywords that you like (e.g. radio/audio / amplifiers / filter / Shortwave / Short Wave /test / testing) into the “looking glass” = search function” and give “enter”. Via that you can find specific video’s (under the say 1600 published). In almost all video’s a schematic is showed, if so: it is a working and well tested electronic circuit. Keywords (again): ”audio”, “radio”, “amplifier”, “filter”, “Shortwave”, “transistor”, “FET”, “oscillator”, “generator”, “switch”, “schmitt trigger” etc; so the electronic subject you are interested in. My books about electronics & analog radio technology are available via the website of "LULU”, search for author “Ko Tilman” there. Or https://www.lulu.com/search?adult_aud... I keep all my YT videos constant actual. Search on YT and avoid my circuits that are republished, re-arranged, re-edited on other websites, giving not probable re-wiring, etc. I take distance from all kinds of fake claims, made via republishing my circuits via the www. Upload 8 February 2026