by author
" data-image-caption="" data-medium-file="https://hackaday.com/wp-content/uploads/2022/06/pd-feature.jpg?w=400" data-large-file="https://hackaday.com/wp-content/uploads/2022/06/pd-feature.jpg?w=800">Recently I needed a dual voltage power supply to test a newly-arrived PCB, but my usual beast of a lab power supply was temporarily at a client’s site. I had …read more (https://hackaday.com/2022/07/02/dual-power-supply-in-a-pinch/)

Not on the Internet
https://hackaday.com/2022/07/02/not-on-the-internet/

Whenever you need to know something, you just look it up on the Internet, right? Using the search engine of your choice, you type in a couple keywords, hit enter, …read more (https://hackaday.com/2022/07/02/not-on-the-internet/)

An Affordable Reference Mic You Can Build Yourself
https://hackaday.com/2022/07/02/an-affordable-reference-mic-you-can-build-yourself/

Reference mics are vital tools for audio work. They’re prized for their flat frequency response, and are often used for characterizing the audio response of a room or space. OpenRefMic …read more (https://hackaday.com/2022/07/02/an-affordable-reference-mic-you-can-build-yourself/)

An Anodiser That Does Gradients
https://hackaday.com/2022/07/02/an-anodiser-that-does-gradients/

Anodising aluminium, the process of electrolytic build up of the metal’s the oxide layer in the presence of dyes to create coloured effects, is such a well-established process that we …read more (https://hackaday.com/2022/07/02/an-anodiser-that-does-gradients/)

Farm Data Relay System: Combine LoRa and 2.4 Ghz Networks Without WiFi Routers And Cloud Dependence
https://hackaday.com/2022/07/02/farm-data-relay-system/

Setting up a wireless sensor network over a wide area can quickly become costly, and making everything communicate smoothly can be a massive headache, especially when you’re combining short range …read more (https://hackaday.com/2022/07/02/farm-data-relay-system/)

Does Hot Water Freeze Faster Than Cold? Debate Continues Over The Mpemba Effect
https://hackaday.com/2022/07/02/does-hot-water-freeze-faster-than-cold-debate-continues-over-the-mpemba-effect/

PA Images / Alamy Stock Photo
" data-image-caption="" data-medium-file="https://hackaday.com/wp-content/uploads/2022/06/Mpemba.jpg?w=400" data-large-file="https://hackaday.com/wp-content/uploads/2022/06/Mpemba.jpg?w=800">Does hot water freeze faster than cold water? On its face this idea seems like it should be ridiculously simple to test, and even easier to intuit, but this question …read more (https://hackaday.com/2022/07/02/does-hot-water-freeze-faster-than-cold-debate-continues-over-the-mpemba-effect/)

Aluminum Foil 20 cm Antenna for 10 m Operation
https://hackaday.com/2022/07/02/aluminum-foil-20-cm-antenna-for-10-m-operation/

Screen capture from featured YouTube video
" data-image-caption="" data-medium-file="https://hackaday.com/wp-content/uploads/2022/07/foil-feature.png?w=400" data-large-file="https://hackaday.com/wp-content/uploads/2022/07/foil-feature.png?w=800">[David], DL1DN, is an Amateur Radio enthusiast with a penchant for low-power (QRP) portable operations. Recently he was out and about, and found that 10 m propagation was wide open. Not …read more (https://hackaday.com/2022/07/02/aluminum-foil-20-cm-antenna-for-10-m-operation/)