Chapter 6



  • A single-band, crystal-controlled, QRP module
  • The transmitter mainframe
  • HF construction methods

Making your own PC boards

“Dead Bug” and “Gouged Board” construction
Superglue “Island Boards”

Coax jumpers
Shielded boxes

  • The complete QRP crystal-controlled transmitter
  • Transistor amplifiers and oscillators
  • How an amplifier becomes an oscillator
  • Class A and Class C amplifiers
  • Stabilizing the operating point, bypass caps, and emitter resistors
  • Quartz crystals – the key to frequency stability
  • The 40 meter QRP circuit

Oscillator and buffer

  • Inductors, RF transformers, and impedance matching
  • Tapped toroid inductors

How to wind them (and mistakes you might make)

  • The final amplifier stages for the QRP

Tuned versus broadband – Use both for best results
Bifilar wound, broadband transformers

How to wind them (and how you might screw up)

Ferrite bead RF chokes, expensive RF power transistors, heat sinks, & output connectors

  • Conquering inductors.

Calculating resonance
Calibrating trimmer capacitors
Calculating turns on powdered iron and ferrite toroids
Chebyshev output low pass filters

  • Keying your QRP

MOSFET power transistors

  • A “spot switch” for the QRP