A Work Of Art That Also Receives AM And SSB

Over the winter, [Michael LeBlanc] thought a good way to spend his time during those long dark nights would be to scratch build his own direct conversion receiver. He was able to find plans for such a project easily enough online, but where’s the fun in following instructions? The final result incorporates what he found online with his own unique tweaks and artistic style.

[Michael] based his receiver on a modified approach to the DC40 created by [Ashhar Farhan], a name likely familiar to readers involved in amatuer radio. He further modified the design by swapping out the audio amplifier for a TDA2003A, and bolted on a digital tuner by way of an Arduino and a Si5351 clock generator. There’s a small OLED to show the current frequency, which is adjusted with a high-quality Bourns EM14 optical encoder so he can surf the airwaves in the comfort and style.

The digital tuner mated to the analog DC40 receiver gives the radio an interesting duality, which [Michael] really embraces with his enclosure design. From a practical standpoint he wanted to keep the two halves of the system in their own boxes to minimize any interference, but the 3D printed case exaggerates that practical consideration into a fascinating conversation piece.

The analog and digital compartments are askew, and their rotary controls are on opposite sides. The radio looks like it might topple over if it wasn’t for the fact that the whole thing is bolted together, complete with brass inserts for the printed parts. The integrated carry handle at the top somehow manages to make it look vintage and ultra-modern at the same time. Rarely do you see a printed enclosure that’s both meticulously designed inside and aesthetically pleasing externally. [Michael] earned his 3D Printing Merit Badge for sure with this one.

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Convert A Speaker To A Battery-powered Amplifying Party Box

[Matt the Gamer] loved his pair of Minimus 7 bookshelf speakers. That is until a tragic hacking accident burned out the driver and left him with a speaker-shaped paper weight. But the defunct audio hardware has been given new life as a single portable powered speaker. Now he can grab it and go, knowing that it contains everything he needs to play back audio from a phone or iPod.

The most surprising part of the build is the battery. [Matt] went with a sealed lead-acid battery. It just barely fits through the hole for the larger speaker, and provides 12V with 1.2 mAh of capacity. He uses an 18V laptop power supply when charging the battery. The PSU is just the source, his own circuit board handles the charging via an LM317 voltage regulator. Also on the board is an amplifier built around a TDA2003A chip. He added a back panel which hosts connections for the charger and the audio input. Two switches allow the speaker to be turned on and off, and select between battery mode and charging mode. As a final touch he added a power indicator LED to the front, and a drawer pull as a carrying handle.