Archive for date: August 8, 2011

I before E except after Hellschreiber « SWHarden.com

August 8, 2011 | Amateur Radio, electronics | By: Mark VandeWettering

Scott Harden had a very cool idea: sending Hellschreiber, an old fax-like teleprinter code invented by Rudolf Hell, using just an Atmel ATMega48 and a canned oscillator. The idea is pretty simple: the canned oscillator will produce a square wave with the same amplitude as the input voltage. So, you simply power the oscillator with […]

More on Dino’s simple common emitter amplifier…

August 8, 2011 | electronics | By: Mark VandeWettering

I hadn’t worked through the biasing calculations for collector feedback common emitter amplifiers before, so I thought I’d do that for the simple one transistor NPN preamp that Dino built as his weeklyhack. But even before I got to it, I was confused by something. Check out the schematic (cribbed from Dino’s post): I was […]