The receiver is a dual dual-conversion, dual dual-image superhet receiver that covers the 40, 30, 20 and 17 meter amateur radio bands. With minor modifications, the 41, 31, 19, and 16 meter SWL bands can be received.
The philosophy behind the project was to help a builder get the receiver working, with the help of the LEDs. Better circuits do not have the option of LED testing, so making one change at a time to improve the receiver is much easier, and hopefully, encourages the builder to study receiver circuits and try them out.
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When building a receiver of this complexity, with an audience that has very little test equipment, self diagnosis of the receiver was a very high priority. Every LED on the board tests circuit functions. It is like having a built in oscilloscope.?
In all the amplifiers, the LED is in the drain/source circuit of the MOSFET, showing the current flowing in that amplifier. If improper current is flowing through the MOSFET, it is quickly observed by the LED. The Mixer LED brightness is a direct indication of oscillator drive, and automatically tests the output of the oscillators and the mixer circuit readiness.
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