Homemade regenerative tube radio

home made tube radio

There are no microcontrollers in this project. In fact you wont find a single transistor. This classic regenerative tube radio, modeled after an early 20th century homebrew is complete with schematic and additional photos. For those who are not familiar with tube designs and for simplicity, the regeneration circuit can be thought of as feedback though this relation may … Read the rest

Etch PCBs with ferric chloride and a sponge

F7Z9JTTFX23V5VV

Etching a printed circuit board generally takes a bit of time and uses a lot of etchant. [TechShopJim] posted a method that uses a sponge to reduce the amount of etchant used while speeding up the entire process. First, a resist is applied using either a sharpie or the toner transfer method. Using gloves to handle everything, he soaked … Read the rest

Arduino Nano updated

arduinonano

The official Arduino Nano design has been updated to version 3.0. Like other new Arduino designs, it’s using the ATmega328 instead of the ATmega168. It’s also a slightly more reasonable $35. The small board is designed to be plugged directly into a breadboard and accessed via mini USB cable. This new design is also two layers instead of four … Read the rest

4 LED RGB controller

4rgbled-angle-rainbow_thumb (Custom)

[Steven] was inspired by the BlinkM and Shiftbrite modules, but really wanted something that could be controlled via RS232. He decided to build his own RGB LED module capable of PWM that fit his needs. He’s using a PIC16F628 microcontroller as the base. Each module has 4 individually addressable LEDs with multiple intensities for each color. The units can be … Read the rest

Parts: 4×20 VFD character display (NA204SD02)

futuba-serial

Futaba makes vacuum florescent character displays that can be used as a drop-in replacement for common character LCDs. VFDs have a wider viewing angle, and generally look cooler.

Futaba’s character displays can be interfaced using the standard 8-bit or 4-bit parallel LCD interface, or a simple two-wire protocol. The protocol type is set by resistors on the back … Read the rest

The Prism: Laser Synth-Guitar

This is an interesting instrument. Part laser harp, part guitar, the Prism seems to have some potential. [Jeff-o] put some major time and effort into refinishing a guitar, building the circuit and putting it all together. He did a great job, the instrument looks fantastic and appears to work. We do have a request though; please post a video … Read the rest