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

Chapter 7

BUILDING A CODE PRACTICE RECEIVER

A simple, direct-conversion receiver
A great first project for a new ham
Excellent sensitivity and good stability
Poor selectivity
Adding 700 Hz audio filtering
High pass and low pass filters
Cascaded bandpass filters increase selectivity
Operational amplifiers
Building with integrated circuits
AM broadcast filter
Getting rid of the image

Chapter 8

POWER SUPPLIES

Line powered power supplies
Power supply safety features
Isolation, 3-conductor cords, fuses, switches, ratings
Supply performance and regulation
Rectification, ripple, chokes, capacitors, & bleeders
Zeners, linear regulators, switching regulators
A QRP regulated power supply
A battery power supply for the radio shack
Solar cell charging, low drop-out regulators
Battery powered shack lighting

Chapter 9

ACCESSORIES FOR THE TRANSMITTER

A straight key
An electronic bug
Building dummy loads
"T" type antenna coupler
A low pass filter
How to stay legal with a homebrew transmitter
Antenna and power relays
Homebrew QSL cards

Chapter 10

VARIABLE FREQUENCY OSCILLATORS

Drift is a big deal today
Low frequency VFOs drift less than high frequency VFOs
JFET transistors
The oscillator circuit
The buffer, final amplifier and output filter
The 50 secrets of avoiding drift
JFETs, single-side PC boards, cast metal box, multiple NPO caps, small variable caps, precision voltage regulation and more
Vernier tuning
Varactor tuning elements – advantages and disadvantages
A precision power supply
A voltage doubler power supply for battery use
Square wave generator with a multivibrator
Squaring up the square wave
Charge pump, diode/ capacitor voltage doubler
Schottky diodes for efficiency
Temperature compensation methods
Positive coefficient capacitive trimmer compensation
How to adjust the compensator
Thermistor/ varactor temperature compensation

Chapter 11

Building a VFO for the higher bands (PMOs)

Old approaches that no longer work
Frequency multiplication
High frequency oscillators
PreMix Oscillator method of frequency translation
A VFO-controlled QRP module
Crystal oscillators are stable, aren’t they?
Crystal oscillator circuits
Butler oscillators and big crystals
Mixers, bipolar transistor and dual-gate MOSFET
Optimum drive requirements
Direction of tuning, drift error cancellation
Multistage filters and filter/amplifiers
The QRP final amplifier stages

Chapter 12

FINAL AMPLIFIERS

The basic features of a modern linear power amplifier
It looked easier in the Handbook
Linear "noise mode" operation
A tuned 50 watt class B amplifier
Ferrite balun transformers
An untuned, sort-of-linear, class B, amplifier
Keying the 50 watt transmitter
A linear Class AB amplifier, this time for sure
Single Sideband (SSB) needs a linear
Biasing without thermal runaway
Clamp diodes prevent runaway
Mechanical construction

Chapter 13

BUILDING A HOMEBREW HF RECEIVER

Building a receiver - an unusual adventure
What’s a reasonable goal?
An "adequate performance" HF communication receiver
Does it have to be so complicated?
Planning your receiver
Direct conversion versus superhetrodyne
Why not single conversion?
Start with a single-band, single-conversion superhetrodyne
How do modern digital receivers do it?
Receiver construction – build with shielded modules connected by thin coax.
The 80 meter preselector
Reception on 80 meter and 160 meters is aided by a tuned transmatch
The Variable Frequency Oscillator
Mixer magic
Mixers will give you lots of static – and howls and squeals
A practical homebrew mixer made from discrete parts – it’s harder than it looks
Dual gate MOSFET mixers
Not all MOSFETS work equally well
Crystal ladder filters – essential for CW
All 9.000 MHz crystals aren’t equal
Using the BFO oscillator to match crystals
Switch in filters with a rotary switch
The IF amplifier
The cascode amplifier strip - variable gain with constant Q
Automatic Gain Control (AGC) - not a luxury
The product detector
Nearly anything works at least a little
The AF amplifier – a vital part of the signal dynamic range
Protecting your ears from strong signals
How Hi-Fi should it be?
Driving a speaker
HF converters for the other ham bands
Crystal oscillators
Bandswitching
Receiver power supplies
Use a linear regulator, not a switching regulator

Chapter 14

OLD-TECH VACUUM TUBE RADIO

How old can radio technology be and still be used on the air today?
Why bother with vacuum tubes?
Glowing filaments, colored plasmas & Jules Verne glass envelopes
Power supplies for tubes
High voltage power supply safety
The old-tech QRP transmitter
Vacuum tube amplifiers
The three roles of the triode filament
RF sinewave oscillator
Quartz crystals
Triode and pentode oscillators
Old-tech voltage regulation – big, crude, expensive, but beautiful
The travails of triode tubes
The oscillator and buffer
The final amplifier – triodes chirp
The transmitter power supply
An inadequate supply from a 1935 radio
A good power supply made from cheap, modern, boring parts
How to check out junk power transformers
A complex but adequate supply made from ancient parts
It works! No one suspects it’s old and it’s a success on today’s 40 meter band
An old-tech receiver
A super regenerative receiver made from ancient tubes
The power supply
Super-regen on the modern hambands
Lots of fun, but not up to modern QRM & QRPs - back to the drawing board!

Chapter 15

THE NOBEL PRIZE FOR SIDEBAND

It can’t be that hard! Want to bet?
The sideband generator – how it works
The 9 MHz oscillator / amplifier
The audio amplifier
The balanced modulator
Building your own crystal ladder filter
Decoupling the power supply leads
Getting rid of RF feedback - RF filtering for all inputs
Tuning and testing
Using the generator for AM modulation and CW
Moving the 9 MHz SSB signal to a hamband
Move the SSB only once!
No wonder most ham rigs are tranceivers
Moving the 9 MHz signal to the difficult HF hambands
Move the VFO first, then mix it with the SSB 9 MHz.
Pick your oscillator and VFO frequencies carefully
Hearing your own VFO in the receiver
The hardest band – 17 meters
Covering the widest band – 10 meters
A linear sideband QRP, VFO-tuned module
All stages must be linear and low distortion
All gain stages should be broadband to prevent oscillation
Sometimes high pass filter output is needed & not the usual low pass
Checking out the generator
Driving a 50 watt linear amplifier

Chapter 16

ANCIENT MODULATION

Defining amplitude modulation
Modulating vacuum tube final amplifiers
Plate, screen & cathode modulation
A "collector modulator"
Converting a MOSFET keyer into a modulator
Generating AM with an SSB balanced modulator
Compensating for non-linearity
Compression by accident
You probably don't need to build a compressor
Ham TV - The old way.
Fun with an ancient flying spot scanner TV camera.

In conclusion:

Homebrew ham radio is never complete - when it works perfectly and does all the latest stuff, the hobby is over. Not likely. Long live homebuilding!

Thanks for reading my book.

73's Frank W. Harris, KØIYE