The DC Receiver Project

Since this photo, I've added an additional filtered RF stage at the input which increases the sensitivity a whole bunch. (A technically educated fellow would include a db figure to show the gain here, but I'll stick to the dabblers definition of "whole bunch." Also added a couple of voltage regulators to provide different voltage levels for the chips, etc.

Anyway, the receiver is now housed in a nice, unmarked, metal case with two knobs on the front and on the back are two switches, one for power and the other to switch in the additional front end stage. Also, on the back, is the antenna, power, and speaker jacks.

The receiver tuning with a ten-turn pot is nice and smooth. It covers the 40 meter CW band. (Of course with a DC receiver you get twice as much for your money, hearing the same signal twice!) I do intend to juggle the capacitors in the tank circuit, using some poly caps with to offset some of the drift that occurs with changes to ambient temperatures. (Someday, when there's a clear spot on the workbench.)