Author: stephenrapley

  • Sputnik 60 years ago today

    Sputnik 60 years ago today

    One of the clearest memories of my childhood is being taken up our steep driveway to the roadside out the front of our house from where there was a commanding view of the western and the southern sky. Sixty years ago today the Russians launched Sputnik and it would have been a few days after…

  • Falling squid poles

    Or how Stephen just realised the error of his thinking for the last few years…. again. Recently I’ve been thinking more about the perennial problem of using squid poles as antenna supports – the fact they all too readily collapse into themselves. This is probably more of an issue with permanently set up poles, but…

  • Oscilloscope music

    The other day I was pottering around Facebook and stumbled across an amusing story via BBC News I think about a young couple who had decided to set themselves the challenge of visiting every one of the over 2,500 railway stations across Britain. I later discovered it’s connected to a Kickstarter project and has a…

  • Back in the loop

    My main project for at least the last 12 months has been building a solid magnetic loop antenna and its companion automatic loop controller. I’ve been roughly tracking its progress at my magnetic loop antenna project page on this blog. As usual, life has got in the way, but I want to get back on track and…

  • US exams at Wyong

    About midway through January, I heard via a Sunday morning WIA broadcast that a group of ARRL Volunteer Examiners was offering to hold exam sessions at the Wyong Field Day at the end of February. I passed my original amateur license exam here in Australia almost 40 years ago. My AOCP (Amateur Operator’s Certificate of…

  • Hygge DX

    Just read about Scandinavian versions of untranslatable concepts (like German’s gemütlich or Portuguese’s saudade) at Quartz. One example is the Danish word hygge (pronounced ‘hooga’)… There’s no direct English translation for hygge, but the word evokes both coziness and togetherness. “It’s not just cozy with a blanket and a glass of wine,” Kurtz tells Quartz. “It’s also interpersonally cozy—so having a few people…

  • Smartlock

    The Smartlock is an accessory for my SGC SG-239 HF Smartuner, and other ATUs they make. It can be bought ready made or built. There are indicator LEDs that signal status (TND, l ‘Z’, 2:1, PHZ, FWD, Auto & Man) on the lower section of the PCB of the SG-239 but they are only visible…

  • Success!

    Great moment this afternoon when the Automatic Loop Controller fired up as it should. Happy days. When I first fired it up, after loading up the Arduino program, all I could see was a dull green glow on the screen. It wasn’t until I remembered a comment from another builder about adjusting the potentiometer on…

  • Antenna tuning by stealth

    One of the most important documents for anyone who wants to know what makes a magnetic loop tick is Leigh Turner VK5KLT’s “An Overview of the Underestimated Magnetic Loop HF Antenna” which can be found on his club website. Midway through building my version of Loftur Jónasson – TF3LJ / VE2LJX‘s Automatic Loop Controller, I came across…

  • Walter Winchell

    I was meandering around the web this morning and stumbled on to a page where famous key collector and curator Tom Perera W1TP had re-created the morse key setup used by Walter Winchell to introduce and punctuate his radio and later TV broadcasts. They were a pair of Vibroplex bugs. I grew up in Sydney in the…

  • Buddipole vertical for 80m

    I spent the pleasant sunny part of the final day of autumn testing a vertical antenna for 80 metres using Buddipole parts for home. The back garden space here is barely 4 metres by 4 metres and for the moment the chimney is out of reach. While I have dreams of a magnetic loop for…

  • Roll your own valves (tubes)

    A few weeks back – in the post about wartime crystal production – I made a tangential reference to my all time favourite YouTube video – Claude Paillard F2FO distilling down to less than 20 minutes his meticulous work making a triode valve, effectively by hand to create a very cute looking valve wearing blue shorts. F2FO,…