40 Meters, 20 Meters, 6 Meters, 70 centimeters. When you hear that kind of
stuff, what does it mean to you? Does it mean 7.0-7.3 MHz, 14.0-14.350 MHz,
50-54 MHz and 420-450 MHz; or maybe do you go looking for a piece of test
equipment with 40 meters on it?
Yes, those are all designations for Amateur Radio bands, or a group of frequencies
that hams are allowed to use. We'll try and sort some it out for you. Here
is a chart of the US Bandplan.
(By the way, there are some words and phrases in dark blue
on this page. You can click on those to get a short explanation or definition.)
HF Frequencies
The portion of the radio frequencies we are interested in start around .5 MHz on the far left side of the scale you see above. That is were the AM broadcast band is. The areas in RED scale above are the amateur radio bands in the what is referred to as the HF Bands. (Also referred to as "Shortwave.") Each of these bands has slightly different characteristics. You can expect each band to perform differently from any other band. What are those differences? These are some characteristics:
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Bands (Meters)
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Characteristics
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160
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1.8-2.0 MHz. Right next door to the AM Broadcast band, Very similar to what you hear on AM Broadcast, quite localized during the day, with long distance capability at night. During the summer months the long distances at night can be several hundreds of miles and during the winter it can be several thousand miles. |
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80
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3.5-4.0 MHz. 80 Meters is very similar to 160 meters but with greater distances especially at night. 80 tends to be a very reliable band less subject to variations of the sunspot cycle and is used a lot for regular net operations and message handling. |
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40
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7.0-7.3 MHz This is many ham's favorite band. It is always open somewhere. During the summer daytime distances of 300-400 miles and night time distances of 1000 miles are quite common. Winter days with 500 miles or more are usual and night time brings intercontinental communications. The downside is that the band is shared with short-wave broadcast from countries outside of North America. Between these interfering signals a ham with a reasonable station can work stations worldwide. Not as affected by the sunspot cycle as 20-10 meters. |
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30
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10.100-10.150 MHz. A lot like 40 meters but can only be used on CW and RTTY. No broadcast interference and has a little longer range than 40 meters also. Daytime ranges of 1000 miles are quite common. |
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20
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14.000-14.350 MHz. It seems like all of the serious DXers hang out on 20 meters. This can be a VERY exciting band. Around the world daytime communications are usual and when the sunspot cycle is peaking 20 can be used around the clock. Very unlikely to be used for short-range communications. The only way to work someone a few hundred miles away would be scatter or possibly "long path". A ground wave signal traveling 50-75 miles might be all you would expect. At the bottom of the sunspot cycle, Openings to other continents are short and rare. |
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17
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18.068-18.168 MHz. Propagation is very similar to 20 meters. This seems to be a very popular band when hams go mobile. |
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15
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21.000-21.450 MHz. A lot like 20 meters but a bit more volatile. More influenced by the position of the sunspot cycle. Much less night time activity than 20 meters but at the peak of the cycle 15 can provide even greater distances. At the bottom of the cycle 15 may not open for days. |
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12
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24.890-24.990 MHz. Very heavily influenced by the sunspot cycle. At the bottom of the cycle it is suitable for very short distance groundwave communications only for long periods of time. At the peak of the cycle it is capable of communications over thousands of miles with a minimum of equipment. |
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10
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28.000-29.7000 MHz. This is the HF band most heavily affected by sunspots and the sunspot cycle and it can be erratic and exciting. Minimum power and simple antennas can bring you a hundred countries in a short period of time when the sunspot cycle is rising towards the peak. Those readers familiar with CB (11 Meters) will be comfortable with how 10 meters reacts. The two bands, 11 and 10 are very close together. Ground wave coverage is 25 miles or so. When you get on 10 meters be sure to contact the 10-10 club. It's lots of fun. |
VHF/UHF
Beginning from the right side of the chart above begins the amateurs VHF and UHF bands.
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Bands
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Characteristics
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50-54 MHz
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Also known as 6 Meters. Good VHF ground wave coverage up to several hundred miles on SSB. 1200 miles or more on openings such as Sporadic-E, F2 layer skip, meteor scatter, aurora, inversions and some EME. Some operators have worked worldwide with fairly modest stations. Some amount of FM and repeater activity. |
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144-148 MHz
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AKA 2 meters. Generally shorter groundwave distances of around 200 miles can be expected on this band with a modest SSB or CW station. Good mobile FM band. Lots of local FM communications on repeaters with up to 150 miles on some "machines". Also a good band for packet radio. There is also lots of satellite activity, EME and terrestrial DX for the hams doing small signal work. Many of the same kinds of openings can be utilized on 2 meters as on 6 meters. |
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1-1/4 Meters. A somewhat underutilized band very much like 2 meters but no satellite activity. This band is not available in many countries other than the USA. |
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420-450 MHz
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Also referred to as 70 centimeters (cm). This is the lowest frequency amateur UHF band. Groundwave coverage is quite short compared to 2 meters due to high absorption. Satellite, EME and terrestrial DXing are popular on this band. Fast scan TV has also found a home on 430 MHz. Lots of FM activity between 440-450 MHz. |
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902-928 |
Very little activity on this band so far due to a lack of suitable equipment. Also this is a shared band with other services.* |
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1200-1300 |
1.2 GHz is a LARGE band with lots of room for experimenters. EME and satellite are popular up here and in some parts of the US there are very active FM repeaters. Not a lot of terrestrial DXing but during contests there is some activity. Antennas for small signal work are quite impressive with lots of elements on short booms. Dishes are practical on this band. |
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Above 1300 MHz
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Amateur radio has allocations all the way from here to light and all kinds of room for experimentation with microwaves and frequencies approaching light. More later. Check here for a list. |
* If you have more information on this band or any of the others, please contact me at webmaster
More questions or comments? Contact thewebmaster.
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