Retro mediumwave detector-radio

thingiverse

Old-school detective radio technology meets 21st-century three-dimensional printing prowess. This straightforward construction yields a reliable medium-wave detector radio that requires no batteries, solely harnessing the transmitted radio energy to function. Designed for a children's event at our ham radio club, this project proves both enjoyable and accessible to people of any age - from nine to ninety-nine. For most popular stations in Europe, approximately twenty-eight turns produce an impedance of fifty to one hundred eighty microHenry, with a frequency range spanning around 550 kiloHertz to 1100 kiloHertz. Instructions Components Needed: 1 x printed parts assembly (coil housing, chassis, slider, and capacitor) 1 x standard ferrite rod (four centimeters in length, having two flat sides) 1 x germanium-type diode (model AA112 or equivalent) 1 x 470 picoFarad ceramic capacitor 1 x high-impedance crystal earpiece (around twenty hundred ohms) Thirty meters of AWG twenty-six lacquered copper wire, four-tenths millimeters thick, for antenna and ground connections Assembly Guide Slide the ferrite rod into the slider; usually, glue is unnecessary. Submerge it in hot water to aid with particularly tight insertions if needed. Ensure a smooth insertion of the ferrite into its coil housing using a file if necessary. Place the capacitor atop to secure the ferrite. Wind twenty-eight turns of lacquered copper wire onto the coil housing and leave ten centimeters loose for connecting. Attach the diode (with black marking pointing away from the coil) along with the capacitor to the chassis (just like depicted on the images). Incorporate the coil onto the chassis, remove two wires' insulators and connect them using the diode and capacitor. Strip both ends of the crystal earplug wires; join one to the free diode end (directed away from the coil) as well as the capacitor. Wrap about twenty meters of lacquered copper wire around the chassis adjacent to the coil to create an antenna, or for support - you can even use holes on the top edge of the coil for additional hold and tension management when wrapping is finished - once this step completes then simply unbind all strands using an open end, remove, attach said strip wires end over to corner diode/ capacitor side Do similar wire wraps around the adjacent part, though reverse positioning – approximately ten meters should be sufficient with similar support features – connect it by both strips removed from previous turn’s edge. Once satisfied take one piece of adhesive tape as an alternative backing or write something small using said adhesion; if needed affix any small item in a cavity inside - you know now that there are several places you could find relief if necessary Now simply twist this back. It should operate! First use Carefully stretch the wire outside of device to form antenna then join remaining strand opposite on another grounding rod device - water heater pipes may work - DO NOT CONNECT ANY WIRE FROM A BATTERY IN A WALL, NEVER Find signal with the sliding device, place frequency you wish to mark inside that hole for scale or any kind you find more fun. Enjoy it - go further building!