Chapter 7A Low-Power Regenerative Radio
When I suggested writing a chapter on regenerative radios, I thought this was going to be a piece of cake. It had to be easy, right? Just add some positive feedback to the system, and magically you get higher gain and selectivity. And after all, I had already designed a vacuum-tube version without a problem back in 2007 that had been featured in EDN Magazine on the Web (www.edn.com/blog/Designing_Ideas/41377-A_super_het_radio_runs_5_years_on_a_C_cell_plus_a_pentode_radio.php).
It turns out that my first regenerative radio was designed with a little luck. Yes, luck sometimes plays a part in successful designs.
However, in trying to duplicate that success from a pentode vacuum tube to transistors—well, that’s ...