Peter Butcher takes a look at the development of RF oscillators from the early days of radio to the present day.

Thelecture covers to the problems encountered from the firstuse of thermionic valves as amplifiers and oscillator. As their useincreased and the technology improved, solutions were sought to manyof the problems.

Alwaysthe thrust was for operation at higher frequencies, as the wavebandsbecame more congested and valve technology evolved to allow operationat higher and higher frequencies.

Widertuning ranges and more powerful oscillators were required fortransmitters. Circuits evolved to allow these two requirements to bemet.

Ultimately,solid state technology was to take over all but the highestfrequencies and powers, but some of the basic problems still existedand the original solutions were still employed.

Spring Junk Sale

At RADARC we're always interested in polar exploration.

This talk covers the amazing journey of Sir John Franklin and his two ships, Terror and Erebus to find a route through the islands of northern Canada to the Pacific.

It will also look at

• Franklin the man
• A history of the two ships
• What went wrong with the expedition
• The subsequent rescue mission to find Franklin and his men
• Modern archaeological evidence giving insight into the fate of the sailors
• Submarine footage of recently discovered ships off the coast of Prince William Island.

Chris Brockley-Blatt, senior
project manager and engineer at Mullard Space Science Labs (MSSL) is with us for an update on the
Solar Orbiter mission.

Venue: Woodford Park Leisure Centre, Woodford Park, Woodley, RG5 4LY
Start Time: 8pm sharp (Chris needs to get away promptly)

The mission is currently scheduled to lift off from Cape Canaveral
launch complex late in the evening of 5 February U.S. time. We are very
lucky to have Chris with us so close to launch.

Chris heads up the solar wind analyser part of the mission:

"We’ve been developing three sensors that will analyse particles in the
solar wind – streams of particles that are ejected by the Sun at speeds
of up to 3 million kilometres an hour and temperatures up to a million
degrees Celsius. We want to know more about the make up and behaviour of
these particle streams."

The engineering challenges are extreme with, for example, huge
temperature differences between the shaded and sunlit parts of the
orbiter.

Chris is that rare character combining an excellent engineer with first
rate organisational, people, management and communication skills.

She sets an example to us as radio amateurs being passionate about
encouraging newcomers into the field of science and technology.

For more information see https://sci.esa.int/web/solar-orbiter

Copious refreshments to be provided as usual.

http://www.rsgbcc.org/cgi-bin/hfcontest_rules.pl?year=2020&contest=NFD

http://www.rsgbcc.org/cgi-bin/hfcontest_rules.pl?year=2020&contest=NFD

http://www.rsgbcc.org/cgi-bin/hfcontest_rules.pl?year=2020&contest=SSBNFD

http://www.rsgbcc.org/cgi-bin/hfcontest_rules.pl?year=2020&contest=SSBNFD

Autumn Junk Sale

The Great RADARC Construction Contest

RADARC Annual General Meeting.

Copious refreshments to be provided.