### Notes to help make this merit badge a little easier

By AA6J Bill Jeffrey
Assistant Scoutmaster and Merit Badge Counselor

6. Do I have do know a lot about electronics to get this merit badge?

You do not have to know a lot about electronics, science, or theory to earn this merit badge. You just have to learn a few major parts of the radio, draw some funny symbols, and learn what three electronic components do. Some very basic notes are given here. You may want to learn a little more about the three components you choose in part (d).

Do the following:

a. Explain the differences between a block diagram and a schematic diagram.

Block diagram: Shows parts of radio station.
Schematic diagram
: Shows how electrical circuit works. It uses schematic symbols (see "d" below) to show the path of a circuit the way a map uses map symbols to show the path of travel on a hiking trail.

b. Draw a block diagram that includes a transceiver, amplifier, microphone, antenna, and feedline.

Remember what we talked about in requirement 4 above. Here we draw a kind of picture to show how it fits together.

c. Explain the differences between an open circuit, a closed circuit, and a short circuit.

An electrical circuit is made up of wires and various electrical components (see item "d" below) which together make up the electronic part of your electrical appliance, in this case a radio. There are 3 types of circuits:

Open circuit: No current flows - There is no electrical contact - For example, when a light switch is off
Closed circuit
: Current flows correctly - For example, when a light switch is on
Short circuit
: Current flows directly to the other side of the circuit - For example, a broken lamp cord where the insulation on the wires is broken so the two wires can touch each other - This is dangerous and can cause a fire. This will hopefully blow the fuse before it causes too much trouble, if the fuse is the right size.

d. Draw eight schematic symbols. Explain what three of the represented parts do. Find three electrical components to match to three of these symbols.

A schematic symbol is a picture which represents one of the (usually small) parts inside electronic equipment like radios. Here are some of the more common ones. You will have to find three actual parts yourself, maybe from a broken radio.