By AA6J Bill Jeffrey
Assistant Scoutmaster and Merit Badge Counselor
3. Where do I tune the radio to find what I want?
Do the following:
a. Draw a chart of the electromagnetic spectrum covering
100 kilohertz (kHz) to 1,000 megahertz (MHz).
b. Label the LF, MF, HF, VHF, UHF, and microwave portions of the spectrum on your diagram.
c. Locate on your chart at least eight radio services, such as AM and FM commercial broadcast, citizens band (CB), television, amateur radio (at least four ham radio bands), and police.
This all sounds and looks a lot harder than it is. First let's explain some of these words, then we'll look at a chart which is a lot simpler than the one in the merit badge book.
The electromagnetic spectrum can be shown on a chart which shows what different frequencies are. For example, you can hear from 20 hertz (Hz) to 20,000 Hz (which is 20 kHz). Remember from math and science that kilo means 1,000 and mega means 1 million. When you tune your boombox to AM you are tuning in kHz, for example, 1000 kHz. FM is in MHz, for example, 100 MHz. Therefore, FM is actually higher even though the number on your dial is smaller.
Requirement (b) is asking about very wide ranges of the radio spectrum.
LF Low Frequency 30 kHz to 300 kHz MF Medium Frequency 0.3 MHz to 3 MHz HF High Frequency 3 MHz to 30 MHz VHF Very High Frequency 30 MHz to 300 MHz UHF Ultra High Frequency 300 MHz to 3,000 MHz Microwave Microwave 1,000 MHz up
You can see that your AM radio is LF and your FM radio is VHF.
d. Discuss why some radio stations are called DX and others are called local.
DX: Distant (not local, usually means out of the country).
Local: Closer, therefore more common usually.
Explain what the FCC and the ITU are.
FCC: Federal Communications Commission, sets rules in US.
ITU: International Telecommunications Union - Sets band plans internationally.
|These notes are designed to help the Scout earn a merit badge that sometimes can seem a bit difficult. They are not intended to replace the Radio Merit Badge book.You will still need to meet with a merit badge counselor.|
3Links about this requirement below:
Copyright Bill Jeffrey 2000-2001. Rights to
reproduce and use for nonprofit purposes given.
Please do not copy this material to another web page. Thank you.
DXing.com has several pages explaining the different radio frequencies:
Frequency Vs. Wavelength is an explanation of kilohertz (kHz), megahertz (MHz), and meters.
Tuning 150 kHz to 30 MHz is a detailed guide to what is found on the lower bands.
The World Above 30 MHz is a detailed guide to what is found on VHF and UHF bands.
Icom Radio's U.S. Amateur Radio HF Band Plan Chart
Hams talk a lot about "DX" (Distant contacts). Here are some links that might give you that same excitement:
Ham Radio Online is a free online magazine. Very well done, plus more info on getting a license.
The Federal Communications Commission governs radio use in the United States.
Their Wireless Telecommunications Bureau includes the
Amateur Radio Service.
While they won't teach you what you need to learn for a license, they do have
how to contact the Volunteer-Examiner Coordinators to take a license test and
Rules for the Amateur Radio Services.
AC6V's DX & Amateur Radio - My friend Rod has the world's best collection of links to amateur radio information.
Last update October 6, 2001