IAN LANG ELECTRONICS
Name | Frequency | Propagation | Uses | Performance Notes |
Very Low Frequency (VLF) | sub 30 kHz | Ground only | Navy Operations Time code signals | Travels very long distances without significant attenuation |
Low Frequency (LF) | 30 kHz - 300 kHz | Ground, and at night is reflected by ionosphere leading to reflections | Long distance broadcasting | Can suffer nightime attenuation |
Medium Frequency (MF) | 300 kHz-3 MHz | Ground, and at night is reflected by ionosphere leading to reflections | Broadcasting over large areas, a region of a country. MW radio. DRM Lower Band. | Can suffer nightime attenuation |
High Frequency (HF) | 3 MHz-30MHz | Bouncing between ground and sky. | Intercontinental Comms. DRM Mid Band | Is dependent on weather and time of day and year. Needs a range of frequencies for continuous coverage. |
Very High Frequency (VHF) | 30 MHz- 300 MHz | Line of Sight and tropospheric | Frequency Modulated broadcasts 88-108MHz Lower part of band for DRM, upper for DAB. | Can only be used for fairly short distances. |
Ultra High Frequency (UHF) | 300 MHz-3 GHz | Line of Sight and tropospheric | 2&3G Mobile Phones. TV Broadcasts. WI-FI HDTV Satellite television | Severely attenuated by terrain features and perhaps the most highly crowded portion after 88-108 MHz |
Super High Frequency (SHF) | 3 GHz-30GHz | Very short and highly focussed distances. | Military &Government, Microwave and satellite links. Radar. | Used for up and download by satellites, does not travel by ground or atmospheric propogation. |
Extremely High Frequency (EHF) | 30 GHz -300GHz | Very short and highly focussed distances. | Military &Government, Microwave and satellite links. Radio Astronomy. | After 30 GHz, wavelengths become so short that attenuation is a problem, and are approaching dangerous levels. |
Sub Division | Band | f min & max | Used For | Comments |
Band I | VHF | 47-87.5 MHz | European TV, radio control, various amateur frequencies including beacons. | |
Band II | VHF | 88-174 MHz | 88-108 FM Broadcasts 108-118 Aeronautical Various distress signals, AM Comms | |
Band III | VHF | 174-230MHz | European TV, DAB 217-230 | |
NATO Band | VHF/UHF | 225-400MHz Although the top end is now occupied by TETRA | Ground Military Uses | KEEP STRICTLY OFF!! Unless you want a big black car pulling up... |
Band IV / V | UHF | 470-862MHz | UK TV Broadcasting. | SDTV, DBV, HDTV PAL UK AM vision carrier lower sideband vestigial FM sound and 25kHz guard band |
L | UHF | 1-2 GHz | Many MOD frequencies exist in this band. ALL transmissions are banned at 1.4 GHz 1.8 GHz is DECT | Other uses in radioastronomy; SETI is at 1.420 |
S | UHF / SHF | 2-4 GHz | 3G mobiles, air telemetry, some MOD frequencies | C Band satelite 3.7 to 4.2 GHz |
C | SHF | 4-8 GHz | Satellite TV in Asia | C Band is impervious to rain fade but suffers from ground interference |
Ku | SHF | 12-18GHz | European Satellite High Level MOD | The topmost band you are likely to come across. |
Band | f min | f max | l min | l max | Wave |
VLF | ~ 15 kHz | 30 kHZ | 20,000 m | 10,000 m | Long |
LF | 30 kHz | 300 kHz | 10,000 m | 1,000 m | Long |
MF | 300 kHz | 3 MHz | 1,000 m | 1 m | Medium/Short at 1.8 MHz |
HF | 3 MHz | 30 MHz | 1 m | 100 mm | Short |
VHF | 30 MHz | 300 MHz | 100 mm | 1 mm | Ultra-Short |
UHF | 300 MHz | 3 GHz | 1 mm | 0.1 mm | Microwave |
SHF | 3 GHz | 30 GHz | 0.1 mm | 0.0001 mm | Microwave |
EHF | 30 GHz | 300 GHz | 0.0001 mm | 0.00001 mm | Microwave |
For VLF the min of approximately 15 kHz is given as radio waves do not propogate much under this. C is given as 300,000,000 m/s but more accurately could be given as 299,792,458 m/s.
Wavelength l = speed of light C divided by frequency f :
l = C / f
Band | f min MHz | fmax MHz | Cap Colour | Channel No. |
A | 471 | 599 | Red | 21-37 |
B | 583 | 727 | Yellow | 35-53 |
C/D | 687 | 847 | Green | 48-68 |
K | 471 | 687 | Grey | 21-48 |
E | 583 | 847 | Brown | 35-68 |
In the United Kingdom analogue frequencies are given a channel number more usually than a frequency. If you need the frequency, it's given by the equation:
fvis= 8n + 303.25
Where fvis is the frequency of the visual carrier and n is the channel number. Then you take off the 0.25
For digital the equation is:
fmux= 8n + 306
where fmux is the centre frequency of the multiplex band you're trying to get.
You are viewing the text version of this site.
To view the full version please install the Adobe Flash Player and ensure your web browser has JavaScript enabled.
Need help? check the requirements page.