Frank Harris - Crystal Sets to Sideband.pdf - Krótkofalarstwo - Scanbook

CRYSTAL SETS TO SIDEBAND

By Frank W. Harris, KØIYE

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

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

(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

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

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

Frank Harris - Crystal Sets to Sideband.pdf

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika: