Tabla de contenidos para February 2024 en Practical Wireless

Although I’m writing this before Christmas, you will be reading it in the New Year, so Happy New Year! Hopefully HF conditions will continue to improve, and the weather too! (Here in Somerset, we seem to have had nothing but rain for the past several weeks – a number of roads across the Somerset Levels have been impassable – the worst for well over 20 years apparently.) There should be plenty to look forward to, radio-wise, with most clubs more or less back to ‘normal service’ these days, plenty of activity on the bands, all being well, rallies and other events gradually starting to pick up again and maybe even some new gear to learn about – it’s very quiet at the moment but there are usually announcements as we…

practicalwireless@warnersgroup.co.uk I have been four times previously to Mauritius but always to travel on to another (DXpedition) location, so I was delighted this year to be invited to join Olof G0CKV and others for a contest operation from Mauritius itself. Olof has been going to Mauritius for this contest (CQWW CW on the last weekend of November) for several years and has built up quite a stockpile of equipment and antennas, so it promised to be a great operation. I try to go somewhere outside the UK most years for this one –the pre-eminent CW contest worldwide. There were seven of us on the team: Olof, Jamie M0SDV, Alan K0AV, Dave WD6T, Denny KX7M, Ranko 4O3A and myself. We arrived at various times and by various routes but were all…

peter.russell@steamrail.co.uk First, an explanation. I think it was in October that my daughter said to me “Dad, do you want an Army morse code thingy for Christmas?” Well, as you might guess, I hadn’t a clue what she was talking about – and neither did she! So, of course, I said yes. A little while before Christmas and she arrives with a rather hefty looking item in a carrier bag and says “Happy Christmas, Dad”. Out of the bag comes a very rusty metal cased ‘thing’ about 10 inches cubed. It had obviously had a hard life, probably languishing in a damp shed for several years, the meter was broken and its paint peeling. OK, so this was going to be a project that would take some time and I…

Keith405625.kh1@gmail.com Garry405625.gs@gmail.com For the Coronation of Queen Elizabeth II on 2 June 1953, foreign-language staff of the BBC’s External Services covered the proceedings from a number of separate positions along the processional route. Places and facilities were also found for 213 commentators who attended from overseas broadcasting services. The Outside Broadcast producer for audio directed the entire sound programme in English from a specially constructed Central Control Room (CCR) housed just outside Westminster Abbey. The outputs of the television cameras in the Abbey and at the West door were also selected and controlled from the CCR, Fig. 1. The individual camera outputs were displayed continuously on the six lower screens while the two above showed the picture leaving the Abbey control room and the actual signal being received from the Alexandra…

gw4vxe@icloud.com Although we have been seeing F2 propagation (often in combination with Es) for a little while, most of the paths we have experienced, from the UK at least, have had a fairly large North – South component to them. It has not been until recently that we have seen some East – West paths open up. Of course, this is to be expected as we head towards the peak of the sunspot cycle, but it is always exciting when it happens. Here at GW4VXE I had started to think about taking the 6m beam down, as it’s a bit vulnerable to the winter storms and there hadn’t been any DX for me in a few weeks. Although I missed it, there was an opening from Western Europe to the…

Gordon King Dear Don, I am the son of the late Gordon J King, he wrote many articles for Practical Wireless. I thought it might be of interest to your readers that on 18 November 2023 a blue plaque was unveiled at 6 New Road, Brixham, Devon in memory of Gordon. I have attached a picture of the plaque that was taken by me. I have also had a family run of his memoirs Kingcups and Dynamos published and there is a copy in Brixham library. Michael King (Editor’s comment: Thank you Michael. Gordon was licensed as G4VFV and wrote extensively for PW over a number of years as well as writing something like 40 technical books. He was born in 1922 and died in 2010. An obituary appeared in…

UPDATING THE AMATEUR RADIO LICENSING FRAMEWORK: Ofcom have published the results of their recent consultation on amateur licensing, with implementation of the changes to take place in three phases. Full details are on the Ofcom website (see URL below). Phase 1 relates to new callsign rules and greater flexibility in respect of several areas of operation, such as removing the requirement for Notices of Variation for a number of activities for which they were previously needed. Phase 2 relates to new Intermediate callsigns, special event callsigns and the number of licences an individual may hold. Phase 3 will give more flexibility in choosing and changing callsigns. Phases 2 and 3 are dependent on the implementation of a new licensing platform, expected to be ready later in 2024. https://tinyurl.com/mu2rtb3a MALTBY &…

practicalwireless@warnersgroup.co.uk Practical Wireless Rating Well made, good value for money. Perhaps a sentiment not echoed by your neighbours but as most amateurs have more than one radio these days, a convenient multipurpose second or even third string to the antenna bow is always welcome. Sometimes you just need that extra capability to monitor something or make a quick contact without having to re-route cables, connectors and adapters. I know that I do so does the discone fit the bill? I first encountered this type of antenna back in the 1980s at the height of the wideband scanning receiver boom, just before the emergency services and mobile phones went digital and spoiled the fun of eavesdropping. Before the days of online, ‘buy it now’ my company commissioned and sold hundreds of…

k4fmh@arrl.net When Rob Sherwood NC0B’s article in the November 2019 issue of QST appeared, it set a mental benchmark for amateur radio operators and manufacturers [1]. The paper, It’s Time to Clean Up Our Transmitters, identified the performance element left behind by transceiver manufacturers: transmit noise. He outlined three key elements of transmitter output that can be problematic. One is broadband transmitter noise. This is most noticed during times of multiple operators in a common vicinity (such as Field Day or any group operating activity). It’s the composite noise that receivers detect from the airwaves. Often, composite noise is called phase noise in ARRL Lab’s graphics summary but it is the AM noise component that is more important to reception rather than purely phase noise. The roll-off of composite noise…

practicalwireless@warnersgroup.co.uk Regular readers will know I use a Hermes Lite 2 transceiver when operating data modes. Whenever I mention it at club talks, I often get asked my opinion on the rig and how I utilise it. As a result, I thought it might be helpful to run through some of the details here. I’ll start with some background on the development of the transceiver. The Hermes Lite 2 is an offshoot of the High-Performance Software Defined Radio (HPSDR) project that’s been running for some time. The project aimed to produce a high-performance SDR design for home construction. The project has gone through many iterations, and the most well-known outcome has been the ANAN series of high-performance transceivers. While the HPSDR project began using a modular approach, the Hermes sub-project…

keith.g4miu@gmail.com I mentioned last month that many years ago I had a homemade two-element 10m Yagi. This was based on a design by Orr W6SAI presented in the Beam Antenna Handbook, Fig. 1. It was constructed using 1in diameter x 10swg aluminium tube for the elements and sections of 2x4in timber to support the antenna. The timber was formed as an ‘H’ with the centre of the H being the boom and the ‘legs’ of the H were the supports for the elements. The matching section for the design, as taken from the book, was made up from some twin mains lead to act as 75Ω twin lead and some RG58 50Ω coax. The overall design was extremely solid and quite heavy. With 10m being active at present I felt a…

practicalwireless@warnersgroup.co.uk From the earliest of times, armies have used some form of signalling. Great Britain was one of the pioneers of radio innovation, having developed the first practical wireless technology system in the 19th century. Radio communication was a vital element of modern warfare, for which the previously dominant landline-based telephone was inadequate. Britain invested heavily in radio research and development between the wars creating a well-established radio industry, so that by the time of WWII radio communication between base and ground troops and their supporting armoured vehicles was essential to support efficient command and control. Royal Armoured Corps WS No. 11. Wireless Set No. 11 was introduced in 1938 and is arguably one of the most successful British military radios of WWII. By 1940, the British Expeditionary Force was…

PORTABLE MILITARY RADIO COMMUNICATIONS OF WWII: Graham Caldwell continues his series of articles on WWII portable radio equipment, including their collecting potential. BIRTH OF THE SUPERHET: Dr Bruce Taylor HB9ANY describes the early development of one of the most important inventions in the history of radio. USING THOSE FIXED POWER SUPPLIES: Dr Samuel Ritchie EI9FZB has, over the years, accumulated a number of fixed power supplies. In a set of three articles he looks at maximising the utility of these type of supplies. HOW TO USE A BASIC OSCILLOSCOPE: Chris Murphy M0HLS looks at using this invaluable lab tool. TRANSMIT QUALITY AMONG MODERN TRANSCEIVERS: Frank Howell K4FMH continues his look at this thorny subject. THE YAESU FT-710 HF TRANSCEIVER: Vin Robinson G4JTR undertakes a quantitative analysis and calibration of the…

SIGLENT has introduced a new range of high-performance oscilloscopes to the UK with the help of Telonic Instruments Ltd. The SDS7000A oscilloscope range has been developed for dynamic markets, such as telecommunications, wireless technologies and high-speed digital technology. In these industries, oscilloscopes are required to provide expanded functionality to meet not just the increasing demands for acquisition and analysis of high-frequency, complex signals but to meet the growing needs of modern applications. The SDS7000A is just such an oscilloscope range, offering 12-bit vertical resolution that not only enables the precise imaging of high-frequency signals, but also offers fine differentiation in vertical detection. More information at: https://tinyurl.com/542x6k8w…

kevin@radio-digital.co.uk Practical Wireless Rating A good buy for DRM enthusiasts. Digital Radio Mondiale (DRM), a digital solution for the AM and FM bands, is very much alive, especially in Asia. Unusually Indonesia is also going to use it in Band III from 174 to 202MHz with the rest allocated to DAB. The fate of DRM on shortwave is mainly in the hands of the international broadcasters although there may be a growing interest among the low-powered European broadcasters such as SE-TA2. I’ve used several DRM capable receivers over the many years since DRM broadcasts have been available. China is currently the leading manufacturer of DRM receivers after production of portable DRM receivers faltered in India. Gospell is the leading manufacturer of AM/FM/DRM receivers but with limited production runs. Gospell GR-228BP…

gm6dx@outlook.com I was looking to interface my Yaesu rotator controller with PC control and I found a few options available online. I worked my way through them looking for a simple low-cost option and came across the K3NG Arduino-based controllers. Like all PC rotator controllers I needed some software and for that I used PST rotator. Having made the decision to make the Arduino based controller I ordered up some parts. • 1 x Arduino R3 (or similar)• 1 x G5500 Shield (I got lots of these made up when ordering some other PCBs but you can order them from Libre Space Foundation)• 4 x 1kΩ resistors• 6 x 4.7kΩ resistors• 4 x transistors (2N2222 or similar)• 6 x 103 capacitors• 1 x enclosure• 1 x 8 pin din socket…

dj.daviator@btinternet.com Farnborough Airport is to be the first UK airport to adopt a next generation ‘hybrid digital control tower’ working position, as part of a new project for NATS and the leading digital tower supplier, Searidge Technologies. The new digital working capability will enable controllers to manage aircraft both by direct visual reference from the control tower windows as they do today, enhanced by a fully interactive panoramic video presentation on screen displaying key parts of the airfield. Strategically placed ultra-high-definition cameras will provide the controllers with views of distant areas or those obscured from the tower. Searidge’s technology platform will give the controllers access to tools that provide improved tracking of the whole airport surface via integration of new ADS-B surveillance and ‘head-up’ labelling of the panoramic video. This…

teleniuslowe@gmail.com Ofcom issued a statement ‘Updating the amateur radio licensing framework’ on the deadline day for this column, 11 December; almost all their original proposals will be implemented, beginning in February. Those with the greatest impact on HF operating were discussed in the September 2023 HF Highlights. The Space Weather Prediction Center, part of the US government’s National Oceanic and Atmospheric Administration, recently issued a revised prediction for Solar Cycle 25, suggesting that activity will peak between January and October this year, rather than in mid-2025 as had previously been predicted. A new trend seems to be for DX stations to supplement the operators physically at the location with one or more stations being operated remotely. The VP6A Ducie Island DXpedition last June had only one ‘local’ station but three…

wiessala@hotmail.com A little more detail came through recently about SDRconnect, the much-talked-about new SDR and server5 software suite by British makers SDRplay. When SDRplay introduced its first SDR (the RSP1) a decade ago, the team could see the need for a wideband SDR receiver, which overcame the basic limitations of the relatively cheap 8-bit dongles then available. The company’s beam of innovation focused on the use of a 12-bit (and later 14-bit) analogue-to-digital conversion (ADC) technology and an extensive set of filters to curtail both ‘phantom’ signals and intermodulation products. At that time – it seems an age ago now – HDSDR, SDR Console and SDR# (‘SDR Sharp’) were among the freely available SDR software packages for radio enthusiasts. By 2016, Airspy had also introduced an SDR of their own.…

g3zlx@juxon.co.uk A long time ago when first licensed I bought a bunch of unusual glass tubes called reed switches at a rally. For want of anything else to do with them, I made a 3-port antenna selector, which has been in operation for several decades since (yes, that long!). As the reeds are magnetically operated, the antenna selection could be placed remotely and operated electrically by switch, rig or computer. Since then, more antennas have appeared at this QTH so a replacement four-port box became necessary and was an opportunity to build a new one. While the reed switches are still available in distribution [1], it seems there are no cost-effective actuating coils on the market any more. Happily, the manufacturer’s data sheet gives enough information to wind one, but…

practicalwireless@warnersgroup.co.uk It is not that long since RadioUser was wound-up and the bringing across of some of its content into this magazine has not been welcomed by everyone, but I know Don has done his best to cater for new readers as well as existing ones. For myself, I welcome the addition of this new content, even though it is not all to my personal taste. I think it important to continue to represent and accommodate the great diversity that encompasses being involved, practically, with wireless, although I hope that we don’t return to the days of ‘build an organ’! It is with this in mind that, this month, I am stepping outside of my normal practice of dealing with amateur band equipment. Recently Don mentioned the Take Twenty series…