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| bands-and-modes [2022/01/29 13:41] – created m0lte | bands-and-modes [2022/01/30 16:54] (current) – m0lte |
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| ====== Bands and Modes ====== | ==== Bands and Modes ==== |
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| This page is meant as a non-exhaustive high level reference of what kinds of activity you will typically find on the common amateur radio bands. It may be UK-centric. | This page is meant as a modern non-exhaustive high level reference of what kinds of propagation and activity you will typically find on the common amateur radio bands. It may be UK-centric. |
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| | === Your contributions welcome! === |
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| | Please edit this page directly or make suggestions via #wiki-discussion |
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| | ^ Band ^ Daytime ^ Night-time ^ Comments ^ Traffic ^ Contests ^ |
| | | 160m \\ 1.81-2MHz | Ground wave (120km) | DX but antennas often compromised | Noisy with summer storms | Data modes, SSB and CW, some AM to be found. | Yes | |
| | | 80m \\ 3.5-3.8MHz | Ground wave / NVIS | DX | Lots of long-winded chat. Massively busy during contests. | Everything, lots of SSB, CW, AM and data | Yes | |
| | | 60m \\ 5MHz | Ground wave / NVIS | DX and local | Channelised, shared with military, caution operating here. Full UK Licence Only | FT8, SSB. No contests. | No | |
| | | 40m \\ 7.0-7.2MHz | Often open worldwide | Often open worldwide | Bread and butter HF band. Massively busy during contests. Mind the upper limit, we have less than the US. | Everything, lots of SSB and CW and data | Yes | |
| | | 30m \\ 10.1-10.15MHz | Open worldwide | Generally closes after sunset | Very narrow data-only HF band. Often great conditions. | Data/CW only, no voice allowed | No | |
| | | 20m \\ 14.0-14.35MHz | Open worldwide | Closes after sunset | Bread and butter HF band. Massively busy during contests. | Everything here. A bit of a zoo. | Yes | |
| | | 17m \\ 18.068-18.168MHz | | | "Polite 20m". 20m non-contest traffic often comes here during the major contests. | SSB, CW, FT8 | No | |
| | | 15m \\ 21.0-21.45MHz | | | Big wide allocation, not much traffic | SSB, CW, FT8 | Yes | |
| | | 12m \\ 24.89-24.99MHz | | | No contests. | SSB, CW, FT8 | No | |
| | | 10m \\ 28.0-29.7MHz | Generally closed but opens when the MUF gets up this high, then comes to life! | Generally closed, but try grey-line to Japan (AM), South America (PM) | Massive wide band, great for local experimentation, FM DX | All sorts, including more FM than the HF bands. New York 10m FM repeater from the UK anyone? Perfectly possible with good conditions. | Yes | |
| | | 6m \\ 50-52MHz | Normally no atmospheric prop | Normally no atmospheric prop | "The magic band". Sporadic E propagation makes this band look like 20m for really short periods in the spring. | FT8, SSB, FM, repeaters! | Yes | |
| | | 4m \\ 70-70.5MHz | Normally no atmospheric prop | Normally no atmospheric prop | Pockets of activity around the country. Similar to 2m. | Mostly FM, but more SSB now the IC7300 exists. | Uncommon | |
| | | 2m \\ 144-146MHz | Normally no atmospheric prop | Normally no atmospheric prop | Pretty much as high as sporadic E propagation ever gets. Tropospheric enhancements can open 2m up as far as southern Europe sporadically. | FM simplex, FM repeaters, APRS (including ISS), FT8, SSB, pockets of AX.25 packet. There's a TV section you can request an NoV for above 2m. Satellites at the top end of the band and CW at the bottom. | Yes | |
| | | 70cm \\ 430-440MHz | Normally no atmospheric prop | Normally no atmospheric prop | Shared with ISM / other users, some geographic restrictions on use, check your licence | FM repeaters, FM simplex, some amateur TV, lots of bleeps and bloops to decode. Satellites in this band too. | Uncommon | |
| | | 23cm \\ 1240-1325MHz | Normally no atmospheric prop | Normally no atmospheric prop | Is present on IC-9700 | SSB, repeaters, beacons, ATV | Specialist | |
| | | 13cm \\ 2300-2450MHz | Normally no atmospheric prop | Normally no atmospheric prop| Used as the uplink band for QO-100 geostationary satellite ops. Usable using transverters generally with 70cm equipment. Unfortunately not open to Foundation licence holders | ATV, SSB | Specialist | |
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| | ==== Notes ==== |
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| | * All bands are "open" all the time within line of sight. This is different from "ground wave". |
| | * A band is "open" beyond line of sight when there is atmospheric propagation. i.e. the MUF (maximum usable frequency) has drifted above the band of interest. |
| | * Generally speaking, the MUF is low overnight and high during the day. Bands will "go long" or "go short" as the critical angle - the angle at which RF reflects off ionosphere layers changes. |
| | * When thinking about propagation, think of the ionosphere as a thick, imperfect, curved, liquid mirror. Not as a perfect solid metal reflector. |
| | * CW is Continuous Wave. Morse code is the usual method of using CW. |
| | * Simplex is radio-to-radio |
| | * NVIS is "near-vertical incidence skywave" - straight up, straight back down again. Only possible on low bands. |
| | * For SSB, 80m and 40m are LSB. The remainder are USB. This is the convention. Data modes are generally USB regardless of band. |
| | * There are two bands below 160m (2200m and 630m). These generally require highly loaded (compromised, lossy) antennas so lots of power in for hardly any power out. |
| | * There are multiple bands above 13cm (9cm, 6cm, 3cm (the only microwave band available to Foundation licence holders), then 24GHz, 47GHz, 76GHz, 122GHz, 134GHz, 248GHz, then a series of Terahertz bands from 275GHz to 3THz available by NoV application). This is highly specialised territory. |
| | * Both of those sets of bands are largely accessible using homebrew equipment only |
| | * It can be somewhat of a surprise to newcomers that chatting around the UK can be surprisingly difficult. If this is your goal, try 160m, 80m, 40m NVIS and/or ground/wave, then VHF (6m, 4m, 2m). Use SSB and horizontal polarisation for more range up here. |
| | * Rule of thumb: No FM on HF, CW at the bottom of each band, then data modes, then SSB/free-for-all. Mind the beacons. |
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| | ==== Some interesting spot frequencies ==== |
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| | ^ Band ^ Frequency ^ What/why ^ |
| | | 2m | 144.800 | APRS | |
| | | 2m | 145.800/825 | ISS downlink | |
| | | 20m | 14.230 | SSTV. 14.233 is digital SSTV too. | |
| | | 20m | 14.074 | 20m FT8 | |
| | | 30m | 10.000 | WWV, American time station | |
| | | 40m | 7.16 | WAB net | |
| | | 80m | 3.76 | WAB net | |
| | | 160m | 1.933 | 1933 net | |
| | | ... | ... | ... | |
