Sunday, August 28, 2011

WT40 Part 1: INTRODUCTION

WT40, Part 1: INTRODUCTION to BUILDING ELECTRONIC STUFF

[ Most recent update:  24 Oct. 2011. (Minor modifications to text.)]





The emphasis here is on learning about electronics by doing it - not electronic theory, but how to put things together and make them work.

The material you find In this series of articles represents a major revision of a project that was previously published on my  WannaTinker   website,  which no longer exists.

NOTE:
Parts 1, 2, and 3 of this series are intended, primarily, for those who have little or no experience with building electronic equipment.

Part 2, Tools, Parts, and Supplies, is an update to a 17 January 2011post here on the WannaTinker blog.

Part 3, Packaging, deals, mostly, with the Modular Building concept that is used for the WT40 transceiver.

Experienced builders are welcome to peruse parts 1, 2, and 3, but may want to start with Part 4 where the building process actually begins.



I CONFESS . . .

   . . . I was born with no knowledge whatsoever about electronics, so everything you see here came from somebody else at some time in the past.

I try to give credit where credit is due, and if I know the source of the material I am using I will site the originator(s).  I have kept notes and diagrams of circuits that have worked for me over the years, and those notes, along with specification sheets from component manufacturers are my main sources of information.  Yes, I sometimes add a tweak or two to the circuits you find here, but I am a technician, not a design engineer.



Building electronic equipment from “scratch” is not everyone’s cup of tea.

CAN YOU DO IT ?

Sure, you can !

Given the desire, along with a bit of patience, persistence, and the ability to use simple hand tools and a digital multimeter (DMM), you can build a variety of electronic gadgets from “ground, up” (the importance of “ground” will be covered later in this series).

I have built, tested, and used every module presented here to insure that they work as intended

Each and every project I build provides entertainment, education, and the satisfaction that comes from messing about with tools, components, and test equipment, not to mention the satisfaction gained from compiling and publishing the pages you see here.

Speaking of satisfaction - - powering-up a radio station you have lovingly assembled from a pile of parts can be a heady experience, indeed. It feels good to be able to say "The rig here is home-brew", and really mean it.

The project(s) presented here are, for the most part, related to amateur (Ham) radio, but the principles and techniques can be applied to other electronic devices.

If you are completely new to electronic building and/or Ham radio, I suggest that you take a look at the ARRL Handbook for Radio Communications, which is available at most any public library, or can be purchases from many book stores, or directly from the American Radio Relay League (ARRL):

  http://www.arrl.org/arrl-store .

One other suggestion for the newbie builder of electronic stuff: find a local Ham radio club in your location and attend a meeting or two. Most clubs are full of Hams eager to help you get your license, and some clubs can actually administer the tests required for the license.  Not only that, but many Ham radio clubs have a "freebie" table set up at their meetings where you may find an ARRL Handbook and other interesting and useful things.

WannaTinker is intended for the inexperienced builder of electronic equipment who, for whatever reason, has decided to build something electronic.  Experienced builders are certainly welcome to follow along as we look into practical ways to assemble and test electronic modules that will eventually be assembled to become a low-power transceiver that can be used on frequencies allocated for amateur (Ham) radio operators.


For those who are not (yet) licensed to operate as Ham radio operators, I hasten to add that you must have a license from the Federal Communications Commission in order to legally operate on any of the Ham radio bands. You can find out about becoming a Ham radio operator by visiting the American Radio Relay League (ARRL) website:

http://www.arrl.org/getting-licensed

MODULAR  BUILDING  TECHNIQUES

After building numerous pieces of electronic gear, I have settled into a modular building technique that has served me well.  By dividing the various circuits that make up a piece of gear into small modules, then assembling the modules into the final unit, the process of building, testing, and (when necessary) troubleshooting is much quicker and easier than other techniques I have tried.

A five-step procedure for building each modules:

[1] Collect all parts required for the module.

[2] Prepare the circuit board.

[3] Populate the circuit board.

[4] Perform initial check-out of the circuit board:
     [] Visual Check
     [] Resistance Measurements
     [] Current Measurements
     [] Voltage Measurements

[5] Operational Test

BUILDING  PROCEDURE  WILL  BE  DETAILED  FOR  EACH  MODULE    

A home-brew project is just that, a   p.r.o.j.e.c.t  -   a work in progress.

I have never built anything that could not be improved upon. Most of my home brew stuff is, therefore, never quite finished. There are some things I have built and used, unchanged, for years. Sooner or later, however, I simply must take the covers off and “improve” the device.

Some work better.

Some look better (or worse). Some show little or no change in appearance or performance.

Some never recover from the “improvement” and end up being cannibalized for parts.

One of my "keepers" is the little QRP transceiver shown below, including a peek under the cover.




The "box to put it in" once housed an “A – B” switch for the serial port on a computer, and measures about 5 7/8” Wide x 2 3/8” High x 6” deep.  Packaging is a  matter of personal preference, and will be addressed later.

As you can see, this little rig is a bit crowded under the cover.  For this WannaTinker series, we will spread things out to make building and assembly easier.  Also, the radio we (YOU and I) are building here will not have some of the optional features included on the version shown in the photo, above.  This series of articles is, after all, about discovering the pleasures of building your own equipment, not about producing the world's best radio.

Having said that, I hasten to add that this little transceiver is capable of world wide communications, given good radio propagation conditions and a good antenna.

Speaking of the world's best radio, the relatively simple radio featured here will certainly not be "the best", but it may turn out to be the best loved because you will have built it with your own hands.

In Part 2, we will take a look at tools, supplies, and parts required for building electronic circuits.

    - END OF PART 1, INTRODUCTION -