History of 4 m

Historically, the British radio amateur had held an allocation in what before the war was known as ‘the ultra high frequencies’ meaning 56 M/C (yes megacycles in those days!). After the war when amateur transmission was resumed the British amateur was allocated 58.5 to 60MHz, but this was available to him for little more than three years, with the spectre of BBC Television looming on the horizon and requiring this band (the first TV station was on 45 M/C’s but the second one, at Sutton Coldfield, was scheduled to go plonk of the middle of the five metre band. There was a commemorative ‘Last Night on Five’ on March 31st, 1949, when the small number of pioneers who used the band foregathered to see the curtain drop).

Very soon the National Society began to lobby for an allocation above the Band One television spectrum and made a point that there existed a long history of ‘Ultra High Frequency’ operation so couldn’t something be found to replace ‘Five’? Indeed it was, and it was called ‘Four’, initially a small chunk from 70.2 to 70.4MHz, but steadily widened as the years passed and as the national society made a case for more room at 4 Metres, and also asked for easement of the restriction on ‘no operation within 50 miles of the Jodrell Bank Radio Telescope’.

The truncated 70MHz band became available to UK amateurs in November, 1956. The 200KHz then available amply accommodated the few who tried their hand at the new band, and today when it extends from 70.025 to 70.5MHz, there is more than enough room.

However, in the earlier days there wasn’t, for much of the band was taken up with wide-band amplitude modulated phone transmissions (FM was years away). It was soon found that AM didn’t travel far, and the CW ethic was always a strong feature of ‘Four’, enabling stations with modest power allowed to enjoy almost nation-wide range.

Part of the folklore of ‘Four’ was that the British were given it in order to provide some QRM to the military, who also shared it. Sometimes during Summer exercises by the military peculiar noises from them may be heard, but the radio amateur virtually enjoys QRM free use of the band for virtually all of the year, apart from Sporadic-E and Tropo manifestations from foreign broadcast stations which share the band.

The ‘lifts’ which became evident early on in the history of ‘Four’ raised hopes that overseas administrations would see fit to give the band to their nationals but none did. There was a modest amount of activity from British sovereign bases such as Cyprus and Gibraltar (there still is) but for most of the time the 70MHz band was ‘peculiar to the British’.

Activity from sovereign bases has been fostered by Service personnel posted to them and inspired by an enthusiasm to try this unusual band. The results achieved under anomalous ‘lift’ conditions made many wish that other overseas countries could be permitted to use it. Although they weren’t, it should be reported that several enterprising Continental operators equipped themselves with 4 metre converters and were able to enjoy cross band contacts with the British.

It is worth emphasising that because ‘Four’ is ‘peculiar to the British’ and is not a world wide allocation, the Japanese don’t provide any of their ‘world-wide’ mass produced rigs for it. Result: much of the equipment used on ‘Four’ is home built. Transverters are also becoming increasingly popular as a means to get going on the band from an existing HF or 144MHz Transceiver.

Antennas are ‘big bedstead like’ compared with the more compact units used on 2m and 70cm. Several excellent commercial designs are available.

Meteor Scatter is sometimes easier on ‘Four’ than on ‘Two’ because reflections from meteor showers appear to last longer.

RSGB awards have been available for 70MHz since 1961. The first Four Metres and Down certificate for 70MHz was awarded to G3EHY in 1953. The first GM to win it was GM2UU in 1967. Requirement is 3 countries and 30 counties. The Senior award requires six countries (just obtainable within the British Isles) and 60 counties. Senior number One was won by G3SKR in 1966. The first GM operated station to win it was GM3KSU/P in 1972.

Firsts between GM and G on ‘Four’ are lost in the mists of antiquity. Sundry requests in the ham radio media for people to come forward to claim say ‘first’ between GM and G or whatever have been greeted either by stony silence or undue modesty.

Jack Hum