Fundamental Basics
for
Amateur Radio Operators






Below are a few of the most fundamental concepts that all amateur radio operators should have seared into their brains. Familiarity with these concepts is required to earn the Technician Class license, and they will be used throughout your ham career.

Ohm's Law



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Power Calculation




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Ohm's & Power Calculation Combined


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Sine Wave
Relationship between Frequency and Wavelength


Frequency - Number of cycles completed in one second. Measured in Hertz.
(Above example = 2 Hz.)
Wavelength - Distance traveled in one cycle. Measured in meters.

Period - Amount of time required for one cycle. Measured in seconds.

Amplitude - Strength of the signal; height of the sine wave.
Usually measured in volts or amperes.


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Frequency - Wavelength Conversion


Where:
λ = Greek letter Lambda = Wavelength in meters
f = Frequency in megaHertz

Note: This conversion is approximate. See the Frequency and Wavelength Conversions section of our Constants and Formulas page for more exact information.

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Radio/Microwave Spectrum


Symbol
Frequency
Range
Wavelength
Range


Description
VLF 3 to 30 kHz 100 - 10 km
Very Low Frequency
LF 30 to 300 kHz 10 - 1 km
Low Frequency
MF 300 to 3,000 kHz 1,000 - 100 m
Medium Frequency
HF 3 to 30 MHz 100 - 10 m
High Frequency
VHF 30 to 300 MHz 10 - 1 m
Very High Frequency
UHF 300 to 3,000 MHz 1,000 - 100 mm
Ultra High Frequency
SHF 3 to 30 GHz 100 - 10 mm
Super High Frequency
EHF 30 to 300 GHz 10 - 1 mm
Extremely High Frequency
- -
300 to 3,000 GHz 1,000 - 100 µm Infrared

See our Electromagnetic Spectrum page for more details.

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Decibels

dB = 10 log10(P1/P2)

Decibels Watts (+/-)
3 dB
x 2
6 4
9 8
10 10
12 16
15 32
18 64
21 128

Example: Increasing the power by 9 dB is equal to multiplying the watts by 8.

See the Power Conversions section of our Constants and Formulas page, and our Decibels page for more information.

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Resistor Color Code



A couple of mnemonics to help you remember the color order:
* Bat Brained Resistor Order You Gotta Be Very Good With
* Badly Burnt Resistors On Your Ground Bus Void General Warranty

See this Wikipedia page for others.

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