Free Quick Reference
The Technician Cheat Sheet
Everything worth pre-loading before exam day, on one page. Print it, pin it, scribble on it.
Ohm's Law & Power
E = I × R
| E = I × R | volts = amps × ohms |
| I = E / R | amps = volts / ohms |
| R = E / I | ohms = volts / amps |
| P = I × E | watts = amps × volts |
| P = E² / R | P = I² × R |
Ex. 13.8 V × 10 A = 138 W; 120 W ÷ 12 V = 10 A
Wavelength
λ(m) = 300 ÷ f(MHz)
146 MHz ≈ 2 m; 28 MHz ≈ 10 m.
Higher frequency → shorter wavelength.
Units
| Current | Ampere (A) | Resistance | Ohm (Ω) |
| Voltage | Volt (V) | Impedance | Ohm (Ω) |
| Power | Watt (W) | Capacitance | Farad (F) |
| Frequency | Hertz (Hz) | Inductance | Henry (H) |
Metric Prefixes
| p | pico ×10⁻¹² | k | kilo ×10³ |
| n | nano ×10⁻⁹ | M | mega ×10⁶ |
| µ | micro ×10⁻⁶ | G | giga ×10⁹ |
| m | milli ×10⁻³ |
Ex. 1.5 A = 1500 mA; 1,500,000 Hz = 1.5 MHz
Decibels (dB)
| +3 dB | × 2 power |
| +6 dB | × 4 power |
| +10 dB | × 10 power |
| −3 dB | ½ power |
5 W→10 W = +3 dB; 20 W→200 W = +10 dB
Components
| Resistor | limits current |
| Capacitor | stores charge (E field) |
| Inductor | stores energy (B field) |
| Diode | one-way valve; LED lights |
| Transistor | amplifies & switches |
| Fuse | opens on overload (hot lead) |
Series: same current. Parallel: same voltage.
Technician Privileges
| 80/40/15 m | CW only (data on portions) |
| 10 m | CW/data 28.000–28.300; SSB 28.300–28.500 |
| 6 m | 50–54 — all modes |
| 2 m | 144–148 — all modes |
| 1.25 m | 222–225 — all modes |
| 70 cm | 420–450 — all modes |
Power: HF max 200 W PEP; above 30 MHz up to 1500 W PEP.
Frequencies to Know
| 146.520 | 2 m FM simplex calling (MHz) |
| ±600 kHz | 2 m repeater offset |
| ±5 MHz | 70 cm repeater offset |
| 50.0–50.1 | CW only (6 m) |
| 144.0–144.1 | CW only (2 m) |
Q-Signals
| QRM | man-made interference |
| QRN | natural noise / static |
| QSB | fading |
| QSY | change frequency |
| QSL | acknowledge / confirm |
| QTH | location |
| QRZ? | who is calling me? |
Modes & When
| FM | repeaters & local simplex |
| SSB | weak-signal / DX (USB on VHF+ & 10 m) |
| CW | narrowest bandwidth |
| FT8 | weak-signal digital |
Antennas & Feed Line
- Coax impedance ≈ 50 Ω.
- SWR 1:1 = perfect match.
- PL-259 for HF/VHF; Type N above 400 MHz.
- ¼-wave 2 m whip ≈ 19 inches.
- Antenna height usually beats more power.
Safety
- RF energy is non-ionizing.
- The station licensee is responsible for RF-exposure compliance — re-evaluate after any change.
- Fuse goes in the hot conductor; never up-rate it.
- Lightning arrester where feed lines enter the building.
- Keep antennas clear of power lines.
Identifying
Give your call sign at least every 10 minutes during a contact and at the end — in English.
Phonetic Alphabet
| A | Alpha | N | November |
| B | Bravo | O | Oscar |
| C | Charlie | P | Papa |
| D | Delta | Q | Quebec |
| E | Echo | R | Romeo |
| F | Foxtrot | S | Sierra |
| G | Golf | T | Tango |
| H | Hotel | U | Uniform |
| I | India | V | Victor |
| J | Juliett | W | Whiskey |
| K | Kilo | X | X-ray |
| L | Lima | Y | Yankee |
| M | Mike | Z | Zulu |