old believers

Dave Jones of EEVblog shows hand soldering of surface-mount parts, including drag soldering and tack-and-reflow of 0.5mm fine-pitch ICs, with solder paste and hot air.

A three-minute demonstration of professional hand-soldering techniques for multi-lead surface mount parts, to IPC class 3 criteria.

This Old House's Ross Trethewey explains MERV filter ratings and how air filtration works, then shows how to build a localized DIY air filter, including a box fan with multiple filters.

A This Old House segment where Richard Trethewey installs a heat exchanger that uses waste heat from a central air conditioner to heat a swimming pool.

A guided Wim Hof breathing session of three rounds at a slow pace, building from a 30 second to a 90 second breath hold. An on-screen bubble animation helps you keep the rhythm.

DIY Perks shows how to modify devices that use older USB connectors so they charge and connect over USB Type-C. He solders in a USB-C connector board and works through cases such as dongle-dependent gadgets and a mouse receiver.

An 11-minute guided Wim Hof breathing session built around an expanding and contracting bubble to pace the breath. Wim breathes along with the viewer over ambient sound.

Dave Jones builds the Evil Mad Scientist discrete-component 555 timer kit, then tests it and explains the internal circuitry of the 555 at transistor level. He finishes with scope waveforms.

Wim Hof guides viewers step by step through his breathing method, with some explanation of the science he cites behind it. It stresses learning from the source and avoiding unsafe settings.

A 1930s Chevrolet training film explaining the principles and development of the differential gear. It builds the idea step by step from first principles to the finished mechanism.

NightHawkInLight shows how to make radiative sky cooling paint from grocery and hardware store materials, including a novel calcium carbonate microsphere synthesis. The paint can cool a surface below ambient air temperature in direct sunlight without electricity.

NightHawkInLight shows how to make ultra-white radiative paint that cools surfaces below ambient temperature without electricity. He walks through the research papers and the household-materials process.

DIY Perks shows how to turn old or smashed TVs and monitors into realistic artificial window lights, using the backlight and Fresnel lens to simulate distant daylight.

A roughly 45-minute vintage US military instructional film that gives a comprehensive overview of celestial navigation, covering sextant use and the theory behind lines of position.