US amateur radio bands 160 meter to 10 meter

 

160 Meters (1.8 – 2.0 MHz): Known as the "Top Band," excellent for nighttime regional and long-distance communication.

80 / 75 Meters (3.5 – 4.0 MHz): Highly popular for regional day and night contacts.

40 Meters (7.0 – 7.3 MHz): Reliable daytime domestic and international communication.

20 Meters (14.0 – 14.35 MHz): The premier worldwide "DX" (long-distance) band available day and night.

15 Meters (21.0 – 21.45 MHz): A great high-frequency (HF) band active during peak solar conditions.

10 Meters (28.0 – 29.7 MHz): Combines local and long-distance propagation, accessible to Technician licensees on segments.

Common Operating Modes

CW (Continuous Wave / Morse Code): Permitted across all amateur bands; highly efficient for weak-signal work. 
Phone (Voice - SSB and FM): Single Sideband (SSB) is standard on HF (LSB on lower bands, USB on 20m and higher); FM is standard on VHF/UHF repeaters. 
Digital Modes: Modern computer-based protocols like FT8, RTTY, PSK31, and packet radio/APRS are heavily utilized for weak-signal tracking and text communication. 




160 Meter ( 1850 kHz )

During the day, ground wave communications over distances of less than 150 km benefit from reliable propagation; at the same time, the strong absorption of the D layer makes communications over greater distances very difficult. At night, when the D layer disappears, the waves can reach the F layer and be reflected. Greater distances are then possible. Atmospheric noise can be very significant and make communications very difficult. Mid-latitude thunderstorms generate a great deal of static, particularly in summer. Best propagation WINTER nights.

80 Meter ( 3500 kHz )

The daytime absorption of the D layer, while less significant than on the 160-meter band, practically closes off this daytime band; however, it remains possible to make contacts up to 400 km using a high angle. As soon as the sun begins to set, intercontinental contacts (as far as the antipodes) become possible. As with the 160-meter band, atmospheric noise is very noticeable and static signals are very important in summer. Best propagation WINTER evenings and nights.

40 Meter ( 7 MHz )

The absorption of the D layer is much lower than on the lower bands, resulting in a near-permanent open signal depending on the propagation mode. During the day, the use of the E layer allows for communications with a range of approximately 800 km under very stable conditions. At night, as soon as ionization begins to decrease, the F2 layer enables highly reliable global contacts. Atmospheric noise is minimal, and static levels, even in summer, are generally lower than signal levels. Best propagation evenings and nights in all seasons.

30 Meter ( 10 MHz )

This band shares characteristics with both the lower (nighttime) and upper (daytime) bands. Atmospheric noise is minimal, and static levels, even in summer, are generally lower than signal levels. During the day, D-layer absorption is negligible, making contacts possible over distances of up to 3000 km. At night, communications with the antipodes are possible. 24/7 use of the F2 layer is feasible. The MUF (Multi-Uniform Frequency) in certain areas may decrease below this frequency. The 30-meter band is the least affected by solar cycles. DX communications on this band are therefore consistently very stable. Best propagation at night in all seasons.

20 Meter ( 14 MHz )

The band is favored by most radio amateurs for global communications. Dependent on the solar cycle, this band is always open for at least a few hours a day for DX traffic via the F2 layer. Short-distance contacts via the E layer are also occasionally possible. During solar maxima, the band can even remain open 24/7. In winter, the band closes relatively early. Atmospheric noise is negligible, even during the day. Best propagation summer days.

 17 Meter ( 18 MHz )

This band behaves like the 20-meter band, but it is more sensitive to variations in the solar cycle (11 years). During periods of low solar activity, the 17-meter band is only open to DX during the day along a north-south axis and at latitudes below 50 degrees. During periods of maximum solar activity, the band is open to long-distance communications all day, into the early evening, and even late into the night. Atmospheric noise is negligible, even during the day.

15 Meter ( 21 Mhz )

This band behaves much like the 17-meter band, except that during periods of low solar activity, it can remain completely closed. Highly dependent on ionization, the 15-meter band is only active during daylight hours, particularly during periods of low solar activity. Traffic is very heavy via the F2 layer and very low, but possible, in the ES (sporadic E) band.

12 Meter and 10 Meter ( 25 and 25 MHz

12 This band benefits from the advantages of the 15-meter and 10-meter bands. It is primarily a daytime band during periods of low or moderate solar activity. During periods of high solar activity, the 12-meter band may remain open even at night. During periods of low solar activity, the 12-meter band is only open to DXing during the day along a north-south axis and at latitudes below 50 degrees; however, during these same periods, the band may remain closed all day. From the 12-meter band onward, ES contacts begin to be possible. ES openings are sometimes observable in winter, but their peak occurs between late spring and summer.

10 and 11 meter This band is very sensitive to variations in the solar cycle and therefore highly variable. It benefits from a large number of propagation modes. During periods of high solar activity, the band opens at sunrise and closes a few hours after sunset. During these periods, a power of just a few watts allows contacts over several thousand kilometers. During periods of moderate activity, the band remains open only for transequatorial communications at low latitudes. During periods of minimum activity, DX communications are completely impossible. ES propagation becomes significant on the 10-meter band. It allows contacts over a distance of approximately 5,000 kilometers. It reaches its maximum between May and August.

Solar cycle

https://en.wikipedia.org/wiki/Solar_cycle

2024 was the best propagation on SW, 2026, 2027 and 2028 will be good also but not like 2024 !

https://webkiwisdrswl.blogspot.com/2025/04/propagation-for-amateur-radio-operators.html?spref=bl

Since 2023 I have listened as an SWL 271 DXCC entity on HF bands.

FT8 frequencies

160 mètres : 1,840 MHz

80 mètres : 3,573 MHz

40 mètres : 7,074 MHz

30 mètres : 10,136 MHz

20 mètres : 14,074 MHz

17 mètres : 18,100 MHz

15 mètres : 21,074 MHz

12 mètres : 24,915 MHz

10 mètres : 28,074 MHz