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QRP with WinlinkQRP (or
lower power transmissions) is a challenge and a passion for many amateur radio
operators. QRP is important because, generally, many hams use much more power for
transmissions than is really necessary. It has the adverse effect of saturating
the radio waves with a lot of excess high frequency energy and drowning or
crowding-out other radio signals. This review was prompted by the experience of Walter (DL7MEK) on board SY Atlantis. Walter and Gisela are now in the seventh year of a slow and meandering circumnavigation onboard their 42 feet steel sloop. Now in the tropics, Walter was seriously concerned about the overheating of his transceiver. The sustained long bursts of power when transmitting was hard on the radio and also could result in frequency instability that would hinder effective radio communications. Walter decided to substantially reduce transceiver power output to 10 Watts only. That, too many might appear very low but it isn't. Report about SY Atlantis on the high seas: Using 10 Watt transmitting in Panama from the Caribbean to the Pacific side: AussieWinlink
was invited to join the crew of S/Y Atlantis for the transit of the Panama Canal
from the Atlantic to the Pacific terminals. This took place in April 2005.
Walter and Gisela are very cautious mariners and without fail access Winlink first thing every morning to request and receive the weather bulletins that
forecast short and longer term projected weather patters. This in itself,
together with any email that needs to be sent or received takes up anywhere from
ten to 20 minutes transmission time, depending on the propagation conditions. The experiments were materially assisted by Gunter (HP1XX) who operates a contest-equipped station from Contadora, a small island in the Las Perlas Group in the Gulf of Panama. Gunter, apart from his regular contesting, operates the amateur Pacific Island Net that assist cruisers approaching Panama with the objective of transiting the Panama Canal either to cruise the Caribbean but more likely to start the "Milk Run" that takes cruisers far into the Pacific. Gunter would call on other mobile marine (/mm) stations with the request for them to attempt and establish contact with S/Y Atlantis. These attempted omni-directional contacts demonstrated that Atlantis' antenna system worked reasonably well but that it could do better. Attention immediately focused on Atlantis' antenna system. Atlantis' antenna consists of an isolated backstay (the steel cables that support the mast from the back of the boat). As Atlantis has two backstays and as the terminals of the antenna at the top are close to the masthead and at the bottom is only about six feet above the deck, it was thought that a lot of the transmitted energy was dissipated through the vessel's rigging to disappear directly into the water rather than leave the antenna as radiated energy carrying a signal over long distances. Talk centered around abandoning the backstay as an antenna and instead install a Shakespeare whip antenna which was thought to have superior performance characteristics. However, Atlantis decided to continue with its present setup and use the planned cruise through Polynesia to really put the system to the test. Obviously, it was also hoped that the new Winlink stations in Australia would significantly improve communications. If there were failures these would be attended to during the planned refitting stop in New Zealand. The table below shows that, at ten watts of power, SY Atlantis was quite successful in contacting Winlink PMBO stations from both the Atlantic and Pacific sides of the Panama Canal. The only notable difficulty was to contact Panama station HP2XBA from the anchorage in Colon at the Caribbean side of the Panama Canal. It was speculated that the mountain range between Colon and Bagala and the relatively short distance did not support the relatively short skip that was needed to contact that station. However, as shown, the stations contacted were all within a range of about 700 to nearly 3,000 miles from Atlantis' location.
Patrick is just one of the many land mobile operators that traverse Australia's vast interior - or the "The Outback." Pat was successful making contacts from his home state, New South Wales (NSW) on Australia's east coast, to South Africa at five (5) Watts of power only. More recently, he was successful with low power radio communications from NSW almost right across the Australian continent to the new Winlink station (VK6KPS) in Western Australia. He writes: QUOTE Hi Tony,
Alfred (DL7MK) and his friends are
the real QRP-dedicated radio amateurs that squeeze the maximum performance out
of Pactor communications halfway around the world. Alfred writes:
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