One of the drivers for innovation within amateur radio was the quest for ever increasing distances.
In 1901 Marconi had managed to send messages across the Atlantic using what he thought were long wavelengths, although there is a lot of discussion about exactly where the main signals were located in frequency.
The challenge of spanning the Atlantic using amateur radio provided just the sort of challenge to which radio amateurs rose.
Foundations for spanning the Atlantic
In 1920 the level of amateur radio activity was low in the UK as life was still returning to normal after the First World War and there were many restrictions on radio equipment.
The same was not true in the USA where amateur radio was becoming very popular and a very large number of licensed stations were active. Also, the US stations were allowed to use powers of up to 1 kilowatt.
With these levels of power reports were soon heard of long distance contacts being made on the short wave bands. In early 1921 US radio amateur Hiram Maxim Percy 1AW managed a two way contact with V. M. Bitz 6JD in California. If contacts like these were possible, then long distance communication across the Atlantic was surely possible on short waves. This only served to further fuel the appetite for contacts across the Atlantic.
As a first stage in the process, it was decided to organise a series of tests in February 1921 to discover whether trans-Atlantic amateur radio communication was possible. Naturally, these tests aroused a considerable degree of interest in the radio press.
The tests were run quite scientifically. Stations in the USA were given specific times to transmit along with specific codes and messages known only to them. In this way it and reports could be properly verified. Unfortunately no signals were heard even though a large number of UK stations took part in the tests. One of the reasons for this failure was put down to the poor receivers that were used in the UK. As the British stations did not have access to the same level of equipment that those in the US did as a result of the on-going post-war restrictions, receivers were still relatively simple.
As it was still thought that the tests were viable to continue, and another series of tests was planned for 17 December 1921.As a result of the perceived reasons for the failure of the original tests, the US sent one of their radio amateurs over. He was a man by the name of Paul Godley and with him he brought one of the new Armstrong Supersonic Heterodyne receivers.
Godley first tested the receiver at a location in Wembley, but found it too noisy. Then he moved his equipment to Ardrossan in Scotland. This was ideal, because it was close to the sea and away from man-made sources of interference. To complement this excellent location, Godley erected a massive Beverage antenna.
Prior to the main tests some preliminary trials were conducted in the USA and Canada, to select the stations best suited for long distance communications. By limiting the number of stations participating, it was hoped that excessive interference caused by the operation of too many stations could be minimised.
When the main tests started, Godley managed to pick up his first station just after midnight on 9 December 1921.
During the first night Godley was only able to decode the callsign - 1BCG, but a couple of days later he managed to copy a full message.
Many in Britain felt that British pride was at stake, so it was fortunate that British stations had also managed to copy messages from across the Atlantic. In fact it was later discovered that the first positive identification of an American station was made a British station, 2KW, during the early hours of 8 December.
Ham radio transatlantic contacts
Once it had been discovered that signals could be heard from across the Atlantic, the next stage was to see if signals could be transmitted back. Thus the concept of a two way transatlantic contact was born. To accomplish this many preparations had to be made. It was felt that the transmitter power 10 or 25 watts permitted at that time by the British Post Office (the UK licensing authority) was insufficient. Accordingly, some special high power permits were issued and some special stations set up. Even so, others with ordinary licences were invited to participate as well.
The dates for the tests were fixed for 12th to 21st December. However, one of the stations with a high power permit located in Manchester managed to hear a Californian station about three weeks before this. Whilst they did not manage to make contact, it was a new world distance record for receiving.
Just as preliminary tests were carried out in America before the previous tests, they were again for these ones. During them, British stations were encouraged to listen, and a good number of American stations were heard.
The results of the main tests were somewhat disappointing. A high power station set up by the Wireless Society of London in Wandsworth, with the callsign 5WS was the only UK station to be positively identified in the USA. Sadly no two way contact was made. It was reasoned afterwards that the high level of activity from America caused considerable levels of interference and confusion.
This set-back meant that another set of tests needed to be organised. This time it was scheduled for the January of the following winter. However, before this date on 27th November 1923, a Frenchman named Leon Deloy 8AB from Nice succeeded in making contact with two American stations Fred Schnell 1MO and John Reinartz 1XAL using Morse on a specially authorised wavelength of 110 metres.
Whilst this contact represented a major milestone in itself, it was even more important because it had been made on the wavelength of 110 metres and not 200 metres which had been used for the previous tests. This showed that even shorter wavelengths could be used.
After the contact with 8AB it did not take long for a British transatlantic contact to be made. On 8th December 1923 British station 2KF made a contact lasting over 2 1/2 hours. Following this many more contacts were made between different stations on both sides of the Atlantic. Although Morse was the favoured mode, AM telephony was used on some occasions when conditions were particularly good.
Amateur radio makes contacts over greater distances
Once these first transatlantic contacts had been made, many other amateurs succeeded in making contacts as well. It was also quickly realised that often the shorter wavelengths around 100 metres or less provided better communications than those around 200 metres.
With people beginning to understand a little more about propagation on these wavelengths, contacts over greater distances started to be made. On 16th October 1924 the signals of Ernest Simmonds 2OD were heard in New Zealand. However two days later Cecil Goyder, 2SZ, at the Mill Hill School in London succeeded in making contact with Frank Bell 4AA in New Zealand. Then a month later Ernest Simmonds made contact with the Australian station 3BQ.
With these successes still hitting the headlines, many stations started to make contacts with others all over the world. Stations were also encouraged to try even shorter wavelengths. Up until now long distance contacts had normally been made at night, but it was soon discovered that long distance contacts could also be made during the day. As a result, the first transatlantic daytime contacts were made in February 1925, and maintained every day for over a month.
Amateur radio provides radio support to distant expeditions
Whilst the value of the short wave bands was quickly grasped, there were not many commercial stations in operation within the few years that followed. This enabled radio amateurs to provide a valuable service in maintaining communications in a number of circumstances where commercial stations were not able to do so.
One example occurred in 1925 when the Mill Hill School station, G2SZ, was able to maintain contact with an arctic expedition when all other means failed. In the same year another British amateur named Gerald Marcuse, G2NM, performed the same service for the Hamilton-Rice expedition in the wilds of Brazil. Messages were passed from the Royal Geographical Society in London to the expedition and back at a time when the expedition was exploring the Amazon.
The radio contacts made across the USA, then across the Atlantic and later to the other side of the globe showed the value of the short wave bands. Previously, the thinking had been that only long wave signals could support long distance communications. These and other commercial tests showed that the short wave bands were able to support global communications. As time progressed and the scientific understanding of radio propagation grew, it was realised that the short wave bands were of prime importance for long distance communications.