Radio Receiver Or Art? Why Not Both?

September 15, 2015 by Al Williams 17 Comments

We’ve heard it said before that you should build things twice. Once to learn how to build it and the second time to build it right. [AA7EE] must agree. He was happy with his homebrew regenerative receiver that he called Sproutie. But he also wanted to build one more and use what he learned to make an even better receiver. The Sproutie Mark II was born.

This isn’t some rip off of an old P-Box kit either. [AA7EE] used a four-device RF stage with FET isolation back to the antenna and a regulated power supply. Plug in coils allow reception on multiple bands ranging from about 3 to 13 MHz. There’s an audio stage with multiple selectable audio filters, and–the best part–a National HRO tuning dial that is a work of art all by itself.

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bc-22e ww2 reciever operating in a hotel

Dodgy Hotel, Beer And A WWII Era Tube Receiver

May 23, 2014 by Will Sweatman 21 Comments

In the luxurious accommodations provided by Motel 8 and armed only with a few tools and a six pack – a pair of amateur radio enthusiasts attempted the repair of an old WWII era BC-224E receiver. They picked up the ~~boat anchor~~ antique receiver, which was in unknown condition, from a flea market while in town for the Dayton Hamvention, brought it back to their hotel and got to work.

The BC-224E came in two parts – the receiver and the power supply. The speaker for the system, which is actually located in the power supply, is driven by a large inductor. Apparently when the receiver was constructed, the permanent magnets of the day were not powerful enough to drive a speaker.

Fortunately, the receiver also came with some schematics, allowing [Gregory] and his fellow radio enthusiast to reverse engineer the power supply. After a few tweaks and cap swaps, they crossed their fingers and plugged it in. Stay tuned to see what happened next.

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Cheap Wireless For Microcontrollers

August 30, 2009 by Jakob Griffith 44 Comments

hr_RF_circuit

Everybody loves microcontrollers, including the Arduino, allowing you to create whatever you imagine. That is unless you want to hack together something wireless. Originally you had to rely on the expensive XBee protocol or other wireless options, but no longer. Hobby Robotics found an extremely cheap transmitter and receiver and wrote a quick guide for wiring them up to an Arduino. Now your wireless projects can come to life, as long as you are within 500 feet and don’t mind 2400bps; minor trade offs compared to the gains of wireless freedom. Final note: You aren’t limited to Arduino, we would love to see someone modify this to work with a PIC or other microcontroller.