Free PCB coupon via Facebook to 2 random commenters

Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three […]

Homebrew 500 watt HF power amplifier

Jeff (K6JCA) has written a series of posts describing his homebrew project 500 watt HF power amplifier: I started this project back in 2016 — I had finished my Automatic Antenna Tuner (seen in the upper-left of the picture, above) and a PA project that would integrate into my FPGA-SDR and ATU system seemed like […]

How to make analog sensor readings with digital I/O pins

Edward Mallon wrote an article describing a technique he used to make analog sensor readings with digital I/O pins: Will this method replace our pin-toggled oversampling? Perhaps not for something as simple as a thermistor since that method has already proven itself in the real world, and I don’t really have anything better to do […]

Teardown of an Amrel PPS 35-2 programmable power supply

Kerry D. Wong did teardown on a single-channel Amrel PPS 35-2 programmable power supply: A while back, I did a teardown on a dual-channel Amrel PPS-2322 programmable power supply, and was quite impressed by its solid construction. Recently, I found another Amrel power supply on eBay and this time it is a single channel version […]

#FreePCB via Twitter to 2 random RTs

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]

App note: Keys to high flexibility

Ever wonder why some wires used on moving attachments last long? Cicoil who innovate the flat ribbon cable has done a lot since early computers on hi-flex wires. Link here Most industrial wire is made up of multiple wire strands, called ‘base strands’, rather than being made of a solid piece of metal. Multiple strands […]

App note: Insulating and Jacketing Materials

Different application calls for different insulations, heres a great info on different insulation and jacketing materials from Calmont wire & cable Inc. Link here Today’s wire user has a wide range of plastic insulating materials to choose from, and yet the selection of a particular dielectric for a specific application frequently is a trade-off in […]

Free PCB coupon via Facebook to 2 random commenters

Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three […]

Monitoring GNSS constellations with Galmon using the LimeNET Micro Ublox-M8 module

Luigi Freitas (PU2SPY) writes: In this blog post, I will explain how I managed to get a GNSS multi-constellation monitor called Galmon working on my LimeNET Micro. The Galmon project is a crowdsourcing tool developed by @PowerDNS_Bert to monitor the health status of GNSS constellations including the GPS, GLONASS, BeiDou and more notably Galileo. The […]

ESP32 LoRa sensor monitoring with web server (Long Range Communication)

Rui Santos posted detailed instructions of how to build an ESP32 LoRa sensor monitoring with web server: In this project, you’ll build a sensor monitoring system using a TTGO LoRa32 SX1276 OLED board that sends temperature, humidity and pressure readings via LoRa radio to an ESP32 LoRa receiver. The receiver displays the latest sensor readings […]

#FreePCB via Twitter to 2 random RTs

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]

Understanding and repairing the power supply from a 1969 analog computer

Ken Shirriff writes: We recently started restoring a vintage1 analog computer. Unlike a digital computer that represents numbers with discrete binary values, an analog computer performs computations using physical, continuously changeable values such as voltages. Since the accuracy of the results depends on the accuracy of these voltages, a precision power supply is critical in […]

Drive an MCP49XX series DAC with an AVR ATmega

Davide Gironi writes: Driving that IC is pretty simple, expecially if you have a dedicated SPI hardware interface, like many microchip has. The ATmega8, used in this example has a dedicated SPI Control Register (SPSR) that one can use to setup the SPI interface. This library can drive more then one MCP49XX of the same […]

Internet connected fire/smoke alarm project

Martin Harizanov blogged about his cheap DIY IoT smoke detector: This project is an upgrade to a previous project of mine – the DIY IoT smoke alarm. It is a more advanced version that uses dedicated hardware rather than the generic “Funky” project + external components. In essence, the module integrates into cheap smoke detectors […]

A look inside a Marconi signal generator

A closer look at a Marconi Instruments signal generator @ jaeblog: Recently I got a Marconi Instruments 2019 signal generator, capable of generating signals from 80Khz up to 1040Mhz. It can also modulate these signals with AM, FM and more. This instrument is from the mid 80s and is, as far as I can test, […]