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Our Friend the Sun

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I had the opportunity to listen to a leading Space Weather Expert the other day, a chat with Professor Gordon P Turnbull. While the questions he was asked may seem a little basic I thought it worth reprinting the transcript here: Can you explain sunspots? Sunspots are dark spots on the surface of the sun that are cooler and less active than the surrounding areas. They are caused by intense magnetic activity and are associated with solar flares and coronal mass ejections. Sunspots can last for a few days to a few months and their number and size varies over time in a pattern known as the sunspot cycle. The sunspot cycle is roughly 11 years long and during the maximum phase of the cycle, there are more sunspots and more solar activity. Sunspots have been observed and studied for centuries and have been found to have a significant impact on Earth's climate and weather. What effect do sunspots have on the earth’s ionosphere? Sunspots can have a significant impact on the Earth's ion...
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Amplifier remote monitor with EMF compliance indication.

By M0WID
One of my recent projects has been building an HF linear amplifier based on some boards purchased from the recent silent key sale.  The amplifier is an A600 version 2.0 by M0HZH, based on two MRF300 LDMOS devices.  The current board version is 2.3 and I have included some of the changes in my version, as well as some other modifications.  The amplifier is capable of 600W CW, I limit it to 300W on SSB to keep things linear.  I have not yet implemented a sampler to provide feedback to the SDR software for predistortion (PureSignal) correction. For this amplifier I developed my own control and monitoring software to properly sequence the relays, bias and so on, select the appropriate low pass filter and to shut down the amplifier should something go wrong that could risk damaging the device, such as high input power, high reflected power, high voltage, high current, high temperature etc.  An LCD touch display on the amplifier allows the various powers, current, tem...
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Mills on the Air 2023

By M0WID
Once again Crawley Amateur Radio Club members gathered at Ifield Watermill on the 14th May to put the mill on the air as part of the Mills on the Air weekend, which coincides with National Mills weekend. We were again blessed with excellent weather, which is just as well as our operating position is outside on the mill pond bank. Dave M0WID was joined by Graham 2E0XDZ and Eddie M7EQC for the initial setting up of the station, while Phil M0TZZ, Richard G3ZIY, Richard G3ANN and Peter G4LEG joined in later. The station is simple and quick to set up and take down, we were on the air perhaps 30 mins after being let in.  It comprised an end fed 1/2 wave vertical for 20m band fed from an ancient Trio TS530S and Graham's new Windcamp Gypsy portable antenna (very neat) fed from his FT857.  The Windcamp Gypsy can be set up as a dipole for any band 40m through 6m and is identical in principle to the ex army portable antenna kindly supplied by G4LEG. Band conditions were poor unfortunatel...
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