10 May 2010

XTAL L.O. for DRM 455-12 converter

The idea of a free-running LC oscillator for my 455-12 DRM converter kept me worried for a few days. With the help of a calculator I found out that:

14060 kHz / 32 = 439.375 kHz

and

455 - 439.375 = 15.626 kHz

So, with a binary counter/divider I can get a LO acceptably close to 12 kHz. I know that DReaM software will decode a DRM signal centered at 15.6 kHz.

Where did I store that 74HC4060 ... ?!