Module 4 - MATH REVIEW

MODULE TOPICS


Reading Assignment

Our TextRead Chapter 2, Pages 2-1 to 2-2 in your text before you continue.

If you have questions after reading the assignment, consult the recommended reading.

The Metric System

Understanding the metric system is imperative to understand electronics theory. Metrics is so much easier to use than the imperial system.

All of our Ham Bands are referred by the wavelength in meters. For example, 80 meters, 40 meters, 6 meters & 2 meters for example.

The reason for using the prefixes to refer to the values of frequency or component value is so that we are not trying to juggle extremely large numbers. An example is 144 Mhz would be 144,000,000 Hz and 1 micro amp would be .000001 amps. I don't know about you, but that many zeros make my head hurt. Imagine adding 1 micro amp (commonly shown as 1 uamp) to 1 micro amp is easily added in your head resulting in 2 micro amps. Ok how about adding .000001 + .000001 amps together!

The most common used prefixes are mega 106 sometimes shown as Meg or M like in 144 Mhz. Another is Kilo 103shown as Kilo or K as in 47 Kohms.

The lesser prefixes are centi 10-2 like in 70 cm. Milli 10-3or milli as in 10 milliamps. Micro or 10-6as in 1 micro amp or 1 uamp.

It would be a good idea to practice how to use your calculator to input and convert several of these metrics until it becomes second nature.

The text covers the metric system well, but does not devote a lot of space to it. Don't let that mislead you. This is a very important concept for you to master.

This table should help in understanding and remembering the metric system.

basic block diagram






Make up a mnemonic to help you remember, for example Pick Micro Mellons - Keep Many Grapes (Pico - Micro - Milli - Kilo - Mega - Giga), what ever works. Remember all you have to do is remember it long enough to put it on your blank page before the test!

QUIZ 4 (4)

We are now going to practice metrics. We will be using some terms that we have not learned yet but will very soon. They are volts, amperes, ohms and more. The idea at this point is to practice the metric prefixes. Probably the best way to learn metrics is to do some problems and learn from them. So, lets do some practice.

You can take the quiz as often as you wish.

Take Quiz 4

Review

In this module you have been introduced to the Metric System especially as it relates to ham radio. More than a few questions require knowledge of the Metric System to ascertain the correct answer.

Recommended reading

View the complete Technician Question Pool in Chapter 11 of your Ham Radio License Manual.

Review the Term Glossary in Chapter 10 of your Ham Radio License Manual

Practice Exams are available at www.arrl.org/exam-practice and there are links to many other test practice sites also.