The local oscillator is an Si5351 synthesiser chip in the form of an SDR-Kits USB-driven module, and the 90 degree phased quadrature signals are generated with a set of 74AC74 flip-flops as a divider.

He found a likely place to tap the IF and used a small resistor to ensure the SDR input didn’t load the radio’s IF stages. Then it is a simple matter of setting some SDR software to the IF ...

A common and inexpensive resistor/capacitor needs to be soldered into one of the cords. The app can receive MOT Slideshow, DRM texts and Journaline, a text news/information feed. AlgorKorea says it’ll ...