The Bands 1111
As hams we have a good variety of bands to choose. From long wave
(136Khz) requiring a very large antenna. To frequencies normally
used for radar (47 GHz)
The LW band
This band is very experimental and is lower in frequency than the broadcast transmitter for Radio 4 (198Khz) Problems with experiments on this frequency will arise from limited equipment, for those yet to acquire construction skills and the low radiation resistance offered by a wire antenna at this frequency. Meaning you will have to put a lot of power in, to get, probably, less than a watt out. But a surprising number of hams do use this band.
The UK longwave ham band is:
2200m 135.7Khz - 137.8Khz
The shortwave (HF) bands
These are the bands between 1.8Mhz and 30Mhz and the traditional listening ground for new 'shortwave listeners' to start on. As an inexpensive radio can be easily obtained for these bands. These bands are not the rich listening ground they were 25 years or more ago, if you are into 'general listening' i.e. Military, government, shipping, aircraft and 'the unusual' As much of this traffic has migrated to satellite, digital or the internet. Although broadcast transmissions and ham radio conversations (QSOs) will be audible at almost all hours on these bands. A SSB (single sideband) reception facility will be essential for listening to ham transmissions on these bands.
Although paring up your shortwave receiver with a computer, can open up some of the digital world to you.
The performance of the bands in this section vary depending upon several factors: Our position in the suns 21 year cycle, time of year and time of day.
These bands are effected by refraction from the ionosphere (skip) which can give worldwide communication some of the time. Or at some times on certain frequencies, absorption virtually limiting performance to line of sight.
All these bands can be received on a shortwave receiver with a simple wire antenna, just get as much wire out as you can, a simple antenna tuner will improve performance by lowering unwanted noise.
The 10 UK shortwave ham bands are:
160m 1.8 - 2.0 Mhz (Topband)
80m 3.5 - 3.8 Mhz
60m 5.26 - 5.405 Mhz (limited to full licensees)
40m 7.0 - 7.2 Mhz
30m 10.10 - 10.15 Mhz (CW and digital modes only)
20m 14.00 - 14.35 Mhz
17m 18.068 - 18.168 Mhz
15m 21.00 - 21.45 Mhz
12m 24.89 - 24.99 Mhz
10m 28.00 - 29.70 Mhz
The VHF & UHF bands
These are the bands between 50Mhz AND 440Mhz and the favorite listening ground for the scanner user. These relatively inexpensive radios work well on these these bands and the more expensive ones can also receive the shortwave bands and even SSB transmissions. These bands have lots of PMR activity (utility services, taxis, aircraft, etc, although the Police went digital in most areas, so can no longer be received).
Ham radio repeaters (relay stations on high spots) these as well as direct (simplex) conversations and outputs from internet linking stations will provide a lot of the activity on these bands, conversations (QSOs) will be audible at almost all hours on these bands.
These bands are mostly line of sight, but are occasionally effected by 'sporadic e' from the ionosphere e layer (skip), which can give long distance or even worldwide communication. Or at the higher frequencies, tropospheric scatter, during high atmospheric pressure, can also increase range.
The 4 UK VHF & UHF ham bands are:
6m 50.0 - 52.0 Mhz (The former band 1 TV band)
4m 70.0 - 70.5 Mhz
2m 144.0 - 146.0 Mhz (to 147.00 with digital use NOV)
70cm 430.00 - 440.00 Mhz
The Microwave bands
These are the bands above 500Mhz and are largely the province of the experimenter as little commercial equipment is made for ham use at these frequencies, with the possible exception of 23cm, which is used for general communication and TV signal transmissions. Some of these higher frequencies are used for satellite uplinks and earth-moon-earth transmissions.
The Microwave ham bands are:
23cm 1240 - 1325 Mhz
13m 2310 - 2450 Mhz
9cm 3400 - 3475 Mhz
6cm 5650 - 5850 Mhz
3cm 10000 - 10500 Mhz
12mm 24000 - 24250 Mhz
6mm 47000 - 47200 Mhz
4mm 75500 - 81000 Mhz
Peter (G4WLI) |
