Short wave converter - for the 20 meter SSB receiver

A descriptive and constructional article for an SSB receiver was published in the June issue of Elektor. The intention was to encourage readers to construct this type of equipment. It was mentioned at the time that the basic design could be used as the basis for other amateur bands providing a converter was available. This means that the receiver frequency must be mixed with an oscillator signal in such a way that the output is tuneable in the range of 14 ... 14.35 MHz. The oscillator frequency together with the special component values required for the specific amateur band required are given in the table. The circuit itself consists of three sections; the input stage (VLF), the oscillator T2 and the dual gate MOSF ET mixer stage T1. Components r T1 Table Band VLF 160 m 80 m 40 m 30 m Frequency (MHz) Crystal (MHz) L1/L2 (.sH) 2.7 8.2 2.2 C1 (nF ) - 3.3 3.3 2.2 C2, C4 C3 (pF) (pF) - - 180 33 180 15 180 10 C11 ... C13 and L6 are a low-pass filter to "clean up" the signal before it is pa