Direct conversion receivers (2):

In the previous instalment of this article we examined the theory behind direct conversion receivers (DCR). In this final instalment we will take a look at three simple projects that are based on the principles discussed in Part 1. Three different designs are selected for testing: the 40 and 75/80·meter bands 'Neopbyte' design by John Dillen': a aü-meter band HF receiver based on the passive DBM designs of Lewallen and Campbell''; and a VLF design. All three designs were fabricated and tested on a common test chassis built especially for the purpose.