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CRYSTAL SETS TO SIDEBAND
By Frank W. Harris, KØIYE
© Frank W. Harris 2002
© Frank W. Harris 2010, Revision 12.
FOREWORD
Dear Radio Amateur,
I began writing this book when I realized that my homebuilt station was almost unique on
the air. For me, the education and fun of building radios is one of the best parts of ham radio. It
seemed to me that homebrewing was disappearing rapidly, so I wrote articles about it for my
local radio club newsletter. My ham friends liked the articles, but they rarely built anything. I
realized that most modern hams lack the basic skills and knowledge to build radios usable on the
air today. My articles were too brief to help them, but perhaps a detailed guide might help revive
homebuilding.
I have tried to write the book that I wish had been available when I was a novice operator
back in 1957. I knew that rejuvenating homebuilding was probably unrealistic, but I enjoy
writing so I pressed on. I thought of myself as Don Quixote battling the windmills of modern
apathy toward the details of technology and science in general. It seemed to be a hopeless quest.
But even if it turned out that no one else cared, I found the project satisfying and extremely
educational.
Modern book publishers don't print books that will have few readers. Because of its
length and numerous color illustrations, this book would be expensive to put on paper. Not
surprisingly, several publishers of electronics books had no interest in it. Fortunately, CDs cost
no more than a postage stamp, so I began sending out CD copies with my QSLs to those radio
contacts that showed an interest in my rig. It was great fun. I often got back thank-you letters
and pictures of their homebrew equipment along with their QSL cards. Eventually, the book
appeared on several websites and was even translated into Spanish.
This book has now been in circulation for 8 years. It is no longer new, so naturally
interest has faded and some of the websites have dropped it. What I should be doing is
continuing to build new designs and continually updating it. However, life must be lived in
series and I seem to be spending more time hiking in the mountains than I do working on ham
radio. My electronics projects these days are nearly all related to mountain rescue. As examples,
as I'm writing this, I have several rope force dynamometers to modify waiting on my workbench
and some data cables for our climbing equipment test tower that I need to rebuild. My mountain
rescue work gets me out in the fresh air and in contact with people face to face. This is important
for retired guys like me. I have added to two articles to chapter 16 about PIC programming and
class D audio amplifiers that came from my rescue work but should also be interesting to hams.
Sigh. Life is too short!
We homebrewers are nearly extinct, but there are still hundreds of us scattered around the
world, some are even in the USA. Yes, there
ARE
American homebuilders! We’re rare, but
thanks to the QRP hobby, the number is growing. Even if we homebrewers don't change the
2.
world, I guarantee you will enjoy learning radio technology and building your own equipment.
Someday I hope to meet you on the air … or at least on the Internet. Hi!
73s, Frank Harris, KØIYE
Frwharris@live.com
CRYSTAL SETS TO SIDEBAND
A Guide to Building an Amateur Radio Station
By Frank W. Harris, KØIYE
© Frank W. Harris 2010, Rev 12
(Note: This document is in PDF format. If schematics and drawings appear
to have insufficient resolution, increase the display magnification.)
Table of Contents
Chapter 1
THE FASCINATION OF RADIO
Exploring the shortwave bands
Growing up in the Morse code era
The joy of building it yourself
A brief history of radio communication
Henry, Maxwell, Hertz, Tesla, and Marconi.
Fessenden, Edison, Flemming, DeForest and Armstrong
The sinking of the RMS Republic and the birth of ham radio
Ham radio in the last 80 years
Becoming a radio amateur
Chapter 2
HOMEBUILDING AMATEUR RADIO EQUIPMENT
What qualifies as homebuilding?
When homebrewing is not appropriate
Barriers to modern homebuilding –
Time, frequency stability, and lead inductance
Basic electrical knowledge
Magnets and static electricity
Voltage, current, resistance, energy, and power
(Illustrated with drawings of water and mechanical analogies)
Conductors, Insulators, and semiconductors
Capacitors, inductors, transformers, and alternators
Home power distribution, transformers at low and high frequencies
Chapter 3
SETTING UP AN ELECTRONICS WORKSHOP
R&D as recreation
How to build radios (or anything else) in your basement
Persistence, read books, keep a notebook, and work in small increments
2.
Minimum tools needed
The ARRL Amateur Radio Handbook
Soldering irons and small tools
Drills & thread taps
Wood carving gouges for making PC boards
>50 MHz Oscilloscope
Frequency counter
Quality multimeter
Lab power supply
Calculator
Lab notebook
Collection of electronic junk
Parts catalogs
Capacitance meter
Test leads and socket boards
Nice-to-have tools
RF and audio generators, spice software, and spectrum analyzer
Chapter 4
HERTZIAN WAVES IN THE BASEMENT
The nature of radio waves
Mechanical and LC electrical oscillators
Antenna and transmission line theory
Crystal set components
LC tuner
PN junction diode detectors
P-type and N-type semiconductors
Detection of AM signals
Homebuilding the parts for a crystal set
The Jamestown diode
The Caribou headphone
Revisiting Crystal Sets in 2006
Learning to troubleshoot
Selective tuning
Recreating Hertz’s radio equipment
Transmitting and receiving as simply as possible
The 1880 ten-meter communicator
Proving that radio waves exist and aren’t just capacitive or magnetic coupling
Demonstrating standing waves to measure frequency
Building homebrew transistors
Bipolar transistors, PNP and NPN
Demonstrating power gain
The Boulder Rock Radio
3.
Chapter 5
GETTING ON THE AIR
- DECIDING WHAT TO DO FIRST
How to earn a license
The rules of the homebuilding game – Whatever makes you happy!
Picking an HF band
Getting acquainted with the HF ham bands, 160 – 10 meters + 6 meters
Instant high quality HF communications
VHF/ UHF handheld transceivers
Building an antenna
Dipoles, regular and folded
Multi-band dipoles
80 meters when you don’t have room for a dipole
The curtain rod vertical
A multi-band vertical antenna
Lightning protection
Chapter 6
BUILDING A QRP HOMEBREW
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
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