Practical takeaway
Electromagnetic-wave properties, frequency/wavelength relationships, wave velocity, and HF/VHF/UHF definitions.
T3B · 12 pool questions
Radio Waves, Frequency & Wavelength
Electromagnetic-wave properties, frequency/wavelength relationships, wave velocity, and HF/VHF/UHF definitions.
Technician exam focus
This group contains 12 questions in the current pool. The teaching below keeps the important tested terms visible while explaining what they mean in normal Amateur Radio use.
1. A radio wave has two fields
Radio is electromagnetic energy. Its electric and magnetic fields are at right angles to one another and to the direction of travel. Polarization is named for the orientation of the electric field.
2. Frequency and wavelength move opposite ways
As frequency goes up, wavelength gets shorter. For a quick amateur-radio estimate, wavelength in meters ≈ 300 ÷ frequency in MHz. That is why roughly 150 MHz is called “2 meters.”
3. All radio waves share the same free-space speed
In free space, radio waves travel at approximately 300,000,000 meters per second, the speed of light. UHF, VHF, HF, and microwave signals all have that same free-space velocity.
4. Know the spectrum labels
The exam expects these ranges: HF = 3 to 30 MHz, VHF = 30 to 300 MHz, and UHF = 300 to 3000 MHz. Hams often name a band by approximate wavelength as well as by frequency.
T3B checklist
- Electric and magnetic fields are at right angles.
- Polarization is defined by the electric-field orientation.
- Higher frequency means shorter wavelength.
- Wavelength (m) ≈ 300 ÷ frequency (MHz).
- Free-space radio-wave speed ≈ 300,000,000 m/s.
- HF = 3–30 MHz; VHF = 30–300 MHz; UHF = 300–3000 MHz.
Exam scope: NCVEC 2026–2030 Technician Class (Element 2), effective July 1, 2026 through June 30, 2030, with February 19, 2026 errata. The current NCVEC pool is the exam authority; explanatory prose here is SPARKA teaching material. NCVEC pool