Radio and Electronics Cookbook

84

CW QRP transmitter for 80 metres

Introduction

This is a relatively simple transmitter design having an output of 1 W. The design is not new, having been described before in other amateur radio publications. The components are all available new and the total cost should not exceed £15.

The circuit

Like other simple transmitters (see An 80 Metre Crystal-Controlled CW Transmitter and A Breadboard 80 m CW Transmitter elsewhere in this book) this one is crystal controlled. This assures frequency stability, but limits the usefulness of the transmitter. The key to increased frequency coverage without a conventional Variable Frequency Oscillator (VFO) is the use of a low-cost 3.58 MHz ceramic resonator. The ‘pulling’ range of a 3.58 MHz ceramic ...