50MHz Band: 50.0 – 52.0MHz
50MHz Band Licence Conditions
In the UK the 50MHz (6m) band between 50.0-51.0MHz is domestically allocated with Primary status, but on the basis of non-interference to other services outside of the UK.
Between 51.0-52.0MHz it is allocated with Secondary status with a power limit of 100W (20dBW), available on the basis of non-interference to other services.
UK 50MHz Band Plan
The idea behind band planning is that it assigns frequencies for certain activities in such a way that all current users can practice the various modes of amateur radio with a minimum of mutual interference.
The 50MHz UK band plan is based on the International Amateur Radio Union (IARU) Region-1 band plan. The plan shows the frequency limits of individual ‘sub-bands’ or segments. The allocation of sub-bands enables the indicated category of users to employ any frequency within that sub-band provided that no appreciable energy falls outside that sub-band. Users must therefore take into account the bandwidth of their sidebands when selecting an operating frequency.
The Transmission Bandwidth’ determines the maximum spectral width (-6dB points) of all emissions recommended in a sub-band. The ‘Mode’ indicates the modulation methods (e.g. telegraphy, telephony, machine generated mode) allowed in a segment. A machine generated mode (MGM) indicates those transmissions relying fully on computer processing, for example JT6M, JT65A, PSK31 or RTTY.
The ‘Usage’ column indicates the main usage of a sub-band or segment. It contains meeting/calling frequencies agreed upon for the convenience of the VHF operators practising specific modes of communication. These frequencies are not part of the adopted 50MHz IARU Region-1 Band Plan and although in the normal amateur spirit other operators should take notice of these agreements, no right on reserved frequencies can be derived from a mention in the usage column.
A detailed look at the 50MHz Band Plan
50.000 – 50.100MHz Telegraphy (CW)
This 100 kHz wide sub-band is allocated to telegraphy (CW) stations with a maximum transmission bandwidth of 500Hz. This are has also been traditionally shared with beacon stations, although many are now migrating up the band to 50.4 MHz create extra room. The primary purpose of beacons is the checking of propagation conditions both for every day amateur use and for special propagation research projects. Newer beacons include MGM such JTxx or PI-4 in their transmissions. Synchronised (time-shared) beacons are now being deployed in the 50-50.010 reserved segment.
50.100 – 50.500MHz Narrowband modes (CW/SSB/MGM)
Narrowband modes with a maximum bandwidth of 2.7 kHz in common with all VHF, UHF and microwave band plans are always found at the bottom of individual allocations. This is where you will find Morse (CW), telephony (SSB) and machine generated mode (MGM) activity such as the poular JTxx modes.
It is very important to note that the area between 50.100 – 50.130MHz is the DX window designated for CW and SSB. contacts between continents only, such as Europe to South America or Europe to Africa. This area of the band should NOT be used for making QSOs within Europe. The same comment is particularly true of the DX calling frequency 50.110MHz which should only be used to establish contacts with stations in other continents before moving away to another frequency.
Most Europe-wide CW and SSB activity will be conducted between 50.130 – 50.300MHz although you should be aware that some countries (such as France) do not have the same band allocations as in the UK.
Cross-band activity is still common, for example between 50MHz and 70MHz and the frequency of 50.185MHz is recommended for this purpose.
Activity between 50.300 and 50.400MHz is mainly using machine generated modes(MGM): 50.305MHz is the PSK center of activity, 50.310-50.320MHz is used for Moonbounce (EME) operation using JT65A and meteor scatter operation using JT6M can be found between 50.320 – 50.380MHz.
50.500-52.000MHz All Modes
This area of the Six Metre band is where you can find a mixture of telephony and digital modes that include FM. simplex and repeater channels, packet radio, Internet voice gateways, automatic packet reporting systems (APRS), facsimile (fax), radio-teletype (RTTY), slow-scan television (SSTV) and RB-DATV.
Within the UK a total of 16 FM repeater channels spaced 10kHz apart have been allocated. The input frequencies lie between 51.220 – 51.370MHz with the outputs shifted 500 kHz lower between 50.720 – 50.870MHz.
Further up the band you will find a total of 10 FM telephony simplex channels. These lie between 51.410 -51.590MHz, each spaced 20 kHz apart. The centre frequency 51.510MHz is designated as the FM calling frequency.
Although the usage column of the band plan indicates that some channels are used by digital modes, internet voice gateways or emergency groups that does not mean you cannot use them for your own communication purposes. It is simply a case of listening on any channel to ascertain locally whether it is in use or not. If you hear no other traffic then you may conduct your contact on any channel you wish to use.
Getting started on 50MHz
One of the reasons why the Six Metre band has become very popular is the availability in recent years of multimode (CW/SSB/FM) transceivers that cover not only the HF bands but also include the 50MHz band. Your choice of antenna is normally dictated by the communication modes that you want to use. If you are only interested in local FM. communication then you should invest in a vertical antenna as this will give omni-directional coverage. If however you want to work long distances (DX) on SSB or CW then it’s best to have some sort of horizontally polarised beam antenna. That’s not to say you can’t work DX with a dipole or a vertical antenna. It just means you stand much more of a fighting chance when using a beam antenna with a bit of gain. As a start you could try a simple 2-element Yagi and perhaps exchange it for something more ambitious when the bug catches.
50MHz Propagation modes
One of the great attractions of operating on the 50MHz band is that it experiences propagation modes common to both the VHF and HF bands. The VHF modes include tropospheric (tropo) propagation, Aurora, Meteor scatter (MS), trans-equatorial propagation (TEP) and E-layer propagation, the most common type being Sporadic-E (Sp-E).
The HF characteristics experienced on the 50MHz band are directly linked to the state of the sun spot cycle. The prime DX mode is F2-layer propagation and occurs during the years around the peak of the solar cycle. At such times the 50MHz band will literally be open to all continents for months at a time.
The pursuit of working world-wide DX is one of the reasons why so many people become addicted to the ‘Magic Band’. The interesting point is that high power and large antennas are not necessary to work long distances. During the summer Sp-E season you can easily work all around Europe with only 10W and a dipole. Many operators including novice licensees accomplish this every year and it is because of the intensity of some of these openings that surprising results can be achieved with very low power.
And the same is equally true when F2-propagation returns. During the last peak in solar activity many low power stations made contacts into North America, South America, Africa, Asia, even as far as Australia on the 50MHz band. Believe me it’s true and it will happen again.
Keeping up-to-date about 50MHz
If you want further information regarding the 50MHz band, then take a look at the UK Six Metre Group (UKSMG) web site. On that site you will find details of daily activity, DXpeditions, international allocations, band plans, beacons, equipment and much, much more.
Take a look also at the RSGB VHF Contest Committee Web site as this gives details of 50MHz activity contests that are held every month.
If you have any suggestions regarding the 50MHz band plan please contact the VHF Manager.
