Dilshan Jayakody writes:
This post is about beat frequency oscillator (BFO) module which is used to receive SSB and CW signals from ordinary shortwave receiver. The original circuit which is related to this post is obtained through the internet and we modify it to get more precise output with commonly available electronic components. (Unfortunately at the time of writing this original link is no longer accessible due to dead link.)
This module consists with two general purpose NPN transistors and we select 2SC828 because of its availability in local marketplace. For the crystal we use commonly available 455 kHz ceramic resonator.
Files available at Elect.wikispaces.com.