Amateur radio frequencies are allocated by the national telecommunication authorities. Each frequency differs in each location in every country depending on its bandlength. Frequencies in each city differ but some frequencies can reach multiple locations if it is strong enough.
However, the International Telecommunication Union is the primary authority that manages the radio spectrum. This includes all radio transmissions including amateur radio frequencies. Certain standards are set to make sure that the different frequencies do not interfere with one another.
As long as the frequencies are within authorized range, the individual amateur stations can freely use any frequency they want. This is subject to the class of license they carry. Also, this can be dictated by the national telecommunication authorities.
Amateur Radio
The transmission modes used by amateur radios vary. These include radioteletype, data, voice and Morse code.
Radioteletype is a type of telecommunications system which has two or more electromechanical printers found in different places that are connected by radio. It includes both the original radioteletype system and the entire group of systems connecting each and all the teleprinters in an area.
Morse code was named after the inventor of the telegraph, Samuel Morse. This is a character encoding scheme consisting of standardized sequences that use dots and dahs to symbolize a character.
All of these enable amateur radio stations to transmit signals to a location or city. However, the strength and bandlength of each frequency still vary and this affects the distance it can travel.
Kinds of Amateur Radio Frequencies
Low Frequency
This type of frequencies travels a distance of up to 2200 meters or 135.7–137.8 kHz. It exceeds the amplitude modulation transmissions that is used worldwide.
In low frequency broadcasting, at least 148.5–283.5 kHz is needed and it should maintain a 9 kHz spacing. This exists only in ITU Region 1 which includes northern to central Asia, Europe and Africa. In other locations, individual stations exist but only a limited number of broadcasting slots are available.
This is the earliest form of radio frequency that helped people communicate especially during the wars. However, it was greatly disadvantageous because of the interference that occurs, particularly with the military.
Medium Frequency
The medium frequency reaches 160 meters or has band of 1800–2000 kHz. This can be found just above the commercial AM broadcast band.
This type of frequency is subject to technical difficulties because of the long distance that it travels. As a result, it is transmitted only at night and rarely during summer. Allocations on this band vary in different countries.
This frequency reaches up to 630 meters or 472–479 kHz. It can be found below the maritime radio band and the commercial AM broadcast band.
High Frequency
High Frequency varies having a distance of at least 10 meters and 80 meters at most. Each frequency is used during particular parts of a day or in different seasons.
- 10 meters
This is best used in long distance activity across oceans for having a bandwidth of 28 – 29.7 MHz. It is greatly used during solar maximum which is a period where the greatest Sun activity occurs during an 11-year solar cycle. When using this during low to moderate solar activity, it is best to do so in low altitudes to decrease interference.
- 12 meters
This has a band of 24.89–24.99 MHz. It is mostly used during daytime. However, it can be used for communication and receiving or identifying distant radio or television signals at nighttime during solar maximum.
- 15 meters
This has a band of 21–21.45 MHz and it is widely used during daytime. It is best used during solar maximum.
- 20 meters
This is a frequency having 14.0–14.35 MHz. It is considered as the most popular frequency for communication and receiving or identifying distant radio or television signals. In this band, QRP operators recognize 14.060 MHz as the primary frequency to be used.
- 30 meters
This has a narrow band of 10.1–10.15 MHz which is also used by non-amateur radio stations. Only Morse code and data transmissions are to be used in this frequency as it is prohibited in some countries like the United States.
In other countries, this frequency is also disallowed for the use of amateurs due to its shortwave spectrum. However, it provides for a reliable means in long distance communication.
- 40 meters
This has a band of 7.0 – 7.3 MHz and is considered as the most reliable band for communicating, receiving or identifying distant radio and television signals at nighttime. During the day, it is a reliable medium of communication within a thousand kilometers at most.
This band is usually used in broadcasts. Due to the high cost of running this band, only commercial broadcasting units are able to use it. As a result, competition among these broadcasting companies is increased.
- 60 meters
This frequency was originally available only in the United States, United Kingdom, Iceland, Denmark and Norway. It has a band of 5MHz per region. Since it is limited, the channel allocation for each country is also limited.
- 80 meters
This has a band of 3.5–4.0 MHz and is best used during nighttime. It can also be used during daytime in a limited capacity.
This type of frequency is best used during winter as there is less atmospheric noise compared to summer. Just like the previous band, only a limited number of countries have access to this frequency. Amateurs are relatively limited to the use of the 300kHZ band or less.
Ultra High Frequency
This is a frequency having at least 300 MHz while a frequency having at least 30 MHz is called a Very High Frequency. This band allows for high-fidelity audio transmissions otherwise known as FM. Very High Frequencies and Ultra High Frequencies have extremely high data transmission capabilities that cannot be interfered with so easily.
Conclusion
There are a number of frequencies that can be used by amateur radio stations as presented in the data above. When engaging in this type of activity, it is best to put in mind the frequencies that you have access to and those that are within the limits of your equipment. It is also ideal to learn more about the different frequencies and how to use them effectively.
