HF bands allocated for radio amateurs and their features

What are Ham Radio Frequency Bands?

Ham bands refer to specific frequency ranges allocated for amateur radio use. These bands allow licensed operators to communicate. The allocation of ham bands is regulated by national telecommunications authorities and overseen globally by the International Telecommunication Union (ITU).

The high frequency (HF) bands for radio amateurs provide a range of frequencies that, when chosen correctly, can ensure reliable communication. These bands, part of the high-frequency spectrum, provide long-distance amateur radio communication. Key bands include 80 meters, 40 meters, 20 meters, 15 meters, and 10 meters, among others. These bands are suitable for various modes, like CW, voice, and data transmissions, with specific bands favored for certain times of the day and propagation conditions.

The 160-meter band, ranging from 1.8 to 2.0 MHz, is technically situated just below the HF range rather than being classified as an MF band. It enables daytime ground wave communication over distances of up to 150 kilometers. During winter evenings, nighttime communication becomes feasible through F-region skip propagation. To consistently enhance signal-to-noise ratio, a magnetic loop receiving antenna is essential.

Moving up, the 80-meter band (3.5–3.8 MHz Region 1; 3.5–3.9 MHz Region 3; 3.5–4.0 MHz Region 2) is the lowest HF band. Like 160m it suffers a daytime D-region absorption. During winter nights signals can propagate halfway around the world via F-region.

The 60-meter band (5.3305–5.3665 MHz) is unique, allowing regional communication on a secondary basis with special licensing, limited power, and restricted modes and frequencies.

At the 40-meter band (7.0-7.2 MHz Regions 1&3, up to 7.3 Region 2) is a popular amateur band due to its clear skip zone during the day, less severe D-region absorption, and reliable worldwide communication via F-region during night. Even during low solar activity this band may be open for worldwide DX throughout the night.

The lower frequency bands (160–40 m) are prone to fadeouts and blackouts. However, the higher HF bands (30–10 m) might become active during the daytime, offering extended and improved global coverage.

The 30-meter band (10.100-10.150 MHz) is a unique communication band that allows daytime communication up to 3000 km and nighttime communication halfway around the world. It operates 24/7 via F-region with minimal variation over the 11-year solar cycle. This band is contest-free and exclusively used for CW and narrowband digital modes.

The 20-meter band (14.000-14.350 MHz) is a popular choice for international communication, renowned for its daylight reliability. It can stay open during solar maximum periods, with skip distance and E-region propagation detected along short paths.

The higher frequency bands (from 17 to 10 meters) are more reliant on sunspots and solar flux.

The 17-meter band, (18.068-18.168 MHz) similar to the 20-m band, is affected by fluctuating solar activity. High solar activity ensures reliable daytime and early-evening long-range communication, while moderate years may only open during sunlight hours. At solar minimum, 17 m will open to middle and equatorial latitudes, but only for short periods during mid day on north - south paths.

The 15-meter band (21.000-21.450 MHz) is a prime DX Band during peak years, but is sensitive to changing activity, closing after sunset. During solar minimum the band is closed except for infrequent north-south transequatorial circuits. Sporadic E is occasionally observed in early summer and mid-winter, but not as common.

The 12-meter band (24.890-24.990 MHz) combines 10 and 15 m bands charactaristics, may stay open after sunset during solar maximums. Moderate solar activity opens to low and middle latitudes during daytime hours, with occasional daytime openings in low latitudes, over north-south paths. The main sporadic-E season from late spring through summer and short openings may be observed in mid-winter.

The 10-meter band (28.000-29.700 MHz) is known for its extreme variations in propagation modes and characteristics. During solar maxima, it is efficient for long-distance F2 propagation, with DX abundant with modest equipment. During moderate solar activity, it opens only to low and transequatorial latitudes around noon. This band shares propagation modes with VHF, such as meteor scatter, aurora, auroral E, and Transequatorial spread-F. Techniques similar to VHF can be effective on 10 meters.

These HF bands let amateur operators communicate worldwide in all kinds of weather, both day and night.

Radio amateurs can also communicate in lower (MF, LF) and higher (VHF, UHF, SHF, EHF) radio frequency bands. See below for frequency allocations for radio amateurs in various countries around the world.

References:

Official ham band plans