Some new PICs like the PIC16F1713 have a NCO that can generate a signal with a frequency up to 16MHz in 16Hz steps. This NCO is used here als LO in a direct conversion receiver. Its possible to receive CW stations as well as the DCF77 signal. The DAC is used to generate output the current frequency in morse code. It would be also possible to use the both opamps as active filter or audio amp.
