Not quite as many members attended the Club Lunch this year, but those who came enjoyed the spring like day and the pleasant company!
Awards made were:
The Dr Little Cup to Paul Bradfield, G1GSN for the construction of a 4M antenna
The G4CBI Cup to Bryan Bourne, M0BIK the best presentation to the club by member.
The G3JKK Shield for Club Support to David Lloyd, G8UOD for his service to the club.
The Round Quize Trophy to Victor, G3JNB since he was a member of the team of 4 who won the Annual Club Quiz. (Team members were: Victor, G3JNB, Alan, G4PSO, Quentin, G0BVW and Bryan, M0BIK)
Other members who won, but who were not present were:
Paul Tewksbury who will receive the G8EMJ Shield for the Major Construction Project and Terry Rose, G4OXD who helped Bryan with the best presentation to the club by a club member.
Brian started by explaining that many persons contributed to the inventions which led to the start of the wireless age. Mentioned were famous names, such as Clark Maxwell, Heinrich Hertz and Edouard Branly. It was Branly’s invention of the coherer that was used in all early detection of radio waves. In 1894 Prof. Oliver Lodge demonstrated reception of signals by wireless, a full year before Marconi. Unfortunately, he didn’t pursue the matter commercially as Marconi did.
Message communications of the time were by telegraph over cables and many people saw no need for anything different. However, the Navy could see the benefit of being able to communicate with ships once they had left harbour. Marconi focused his attention on that aspect and in 1901 the first high power transmitter was built at Poldhu in Cornwall. High power equipment was also fitted on ships being built at that time. However, the communications were not primarily for safety or nautical aspects, but for the convenience of passengers who wanted to send messages at 2 shillings and sixpence each, an eye watering £55. in today’s money!
After the Titanic disaster, authorities agreed that ships should carry wireless as a safety measure and provide a full time radio watch. 1910 to 1920 saw the end of spark transmissions, mainly due to the invention and use of the thermionic valve which allowed amplification of signals and ushered in the era of voice communications.
Brian had a display of working Morse tape inkers and coherers which members were invited to inspect and try out! Not the usual museum pieces under glass!
Speaking to a full house, Jim explained the weather related propagation modes most associated with VHF/UHF. By knowing the signs, an operator might pick the best time to be on the air. The main modes of propagation for the higher bands described by Jim were Sporadic E and Tropospheric Ducting and although weather related, the two modes have different properties. Being able to differentiate means the operator could possibly know what to expect and what results might be obtainable.
Various weather situations were explained and how they impact propagation. Jim pointed out that by listening for beacon signals one might know when paths are open and in which direction. Some discussion followed about the part the Jet Stream plays in controlling the weather and how the highs affected could propagate signals for long distances.
Jim then gave a brief look at modern forecasting methods and how a certain percentage of reliability is achieved, especially for businesses that could be affected by unexpected weather extremes.