Cheatography

SARL Exam Cheat Sheet (DRAFT) by NeelsK

SA Amatuer Radio League Exam

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Units

 pico p ÷1 000 000 000 000 10-12 nano n ÷1 000 000 000 10-9 micro µ ÷1 000 000 10-6 milli m ÷1 000 10-3 kilo k •1 000 103 mega M •1 000 000 106 giga G •1 000 000 000 109

Resistor Color Codes

 Color Digit Multiplyer Tolerance Black 0 • 1 Brown 1 • 10 1% Red 2 • 100 2% Orange 3 • 1000 Yellow 4 • 10 000 Green 5 • 100 000 Blue 6 • 1 000 000 Violet 7 • 10 000 000 Grey 8 • 100 000 000 White 9 • 1 000 000 000 Gold 5% Silver 10%

Ohm's Law

 V = IR Volts = Amperes • Ohms

Kirchoff's Laws

 Kirchoff's Current Law: I``IN``=I``OUT`` Kirchoff's Voltage Law(1) The voltage between any two points in a circuit is equal to the sum of the voltage drops along any path connecting those points Kirchoff's Voltage Law(2) The sum of the voltage drops around any closed circuit is zero

Resistors in Series

 V``1``=IR``1`` Ohm's Law V``2``=IR``2`` V``TOTAL``=V``1``+V``2`` Kirchoff's Voltage Law ∴V``TOTAL``=IR``1`` + IR``2`` ∴V``TOTAL``=I(R``1``+R``2``)

Resistors in Parallel

 I``1``=V/R``1`` Ohm's Law I``2``=V/R``2`` I``TOTAL``=I``1``+I``2`` Kirchoff's Current Law ∴I``TOTAL``=V/R``1`` + V/R``2`` Applying Oh's Law to the whole circuit: V/R``PARALLEL``=I``TOTAL``=V/R``1``+V/R``2`` ∴1/R``PARALLEL``=1/R``1``+1/R``2``

Bands

 160 Meter 1.8 MHz 80 Meter 3.5 MHz 40 Meter 7 MHz 20 Meter 14 MHZ 17 Meter 18 MHz 15 Meter 21 MHz 12 Meter 24 MHz 10 Meter 28 MHz 6 Meter 50 MHZ 2 Meter 144 MHz 144-146 MHz 70 cm 420 MHz 430-440MHz