Practical Wireless的February 2026目录

The Bolton Wireless Club recently embarked on a project that involved launching a High-Altitude Balloon (HAB) to the edge of space carrying a 144MHz Morse beacon. The flight was very successful lasting for two and a half hours and reaching a height of 95000ft. During this time the beacon constantly sent Morse code and was received by many stations around the country. (PW November 2025, p.24) I have been asked a number of times about the beacon circuit and software that I used, so I have presented the circuit and details as a construction project. The VHF Beacon circuit is simple to build, uses fewer than 20 components and costs less than £20, an ideal ‘Take 20’ project for anyone who would like to construct and experiment with one. Although…

Last month I described a couple of ways to measure the effectiveness of Common Mode Chokes which could be used on the coaxial line between the antenna and operating position. Two methods were shown, one using a jig (or fixture) which connected the VNA to the outer braid of the coax cable on the choke and the other method where the VNA leads were clipped to the choke’s RF connectors on the ‘ground’ side, where in the example, the leads were clipped to the outers of the BNC sockets used on the choke. In both instances the chokes were formed with coaxial cable wound over toroid cores and, as just mentioned, the VNA was connected to the outer of the coaxial cable as this is where common mode currents will…

In the first article we looked at using online SDR receivers as a starting point for Hobby Radio. In that article, we saw how Medium Wave stations from around the world can be received with just a computer with an Internet connection using the Kiwi SDR platform [1]. In this article we will stay with Kiwi but start to explore analogue signals on shortwave (also called ‘High Frequency’, HF). The aim of these articles is to give you tasters of what hobby radio can offer so I will not go into great detail so leaving you room to explore the many different aspects of the hobby. Eventually, you may want to buy equipment of your own so use free SDR receivers to find out which areas of the hobby you…

Send your letters to: Practical Wireless Letters, Warners Group Publications plc West Street, Bourne, Lincs PE10 9PH E-mail: practicalwireless@warnersgroup.co.uk January PW Dear Don, Well, that piece all about Oliver Heaviside, written by G7ETW, sort of whetted my appetite. And the funny thing is, I was contemplating a short piece about Heaviside myself a few months ago. So having got wind of Tony’s efforts, I put it on the back-burner. Reading through his article, perhaps it was a good idea to put my scribbles on hold. My interest in Heaviside was the fact that like a few other less well-known pioneers, I thought he deserved the oxygen of publicity (as Tony pointed out, why he remained “bitter for most of his life”). If only because of his Heaviside Layer with the…

Ever fancy taking a walking stick to operate portable HF radio? What if the ‘walking stick’ was a lightweight vertical antenna that would have low SWR on 80-10 metres? To boot, it also packs down into a two-foot long padded case for easy walking. Here is what I have done to build one. Inspired by the Ham Radio Rookie YouTube presentation on his ‘carbon fibre squid pole EFHW antenna’, I began experimenting with it. The attractiveness of a multiband HF portable vertical using only a metallic tape applied to an inexpensive telescoping carbon fibre pole is compelling indeed. Most hams operating portable are by now aware of the lightweight Faraday Cloth used as a counterpoise. Ben VE6SFX and I communicated through comments on his YouTube video where he said this…

In the hope that my last two articles have had some impact on a few of those newly licensed who may have been persuaded to learn CW, I decided to write a follow-up type of article as a bridge that can be crossed to help those who would like to try the mode for the first time. I am not sure if it would carry the same attraction as it did when I was first licensed, but I can only hope! In teaching Morse I do lean heavily on some Big P words. These are extremely important – I may have mentioned them before! The Four P’s: Your bridge from Practice to Performance So, you took the challenge. Maybe you’re one of the youngsters, or indeed a mature adult, who…

The wide availability of low-cost GPS receiver chips has led to ever more amateur radio equipment and test gear being supplied with built-in GPS receivers. It seems only a short time ago that we were buying GPS-tempered clock oscillators to provide stable clock sources for transceivers and test equipment. We were also investing in 10MHz distribution amplifiers to provide buffered and filtered feeds within the shack. The new problem we’re facing is how to share GPS antennas between devices with their own GPS receivers. On the face of it, we can solve this with a simple power divider. However, most GPS antennas are active units that require a 3.3V bias-tee DC supply. As a result, there is demand for dedicated GPS antenna splitters, but these seem very expensive, with many…

Mark Savage M0XIC wrote, saying, “The next scheduled 145 Alive Event is entitled 145 Alive (+more 144) and will take place on Saturday 7 February 2026 from 12 noon to 3pm local. “We have added 144 SSB at the request of a number of operators within the group and we will review its success or otherwise after the event. With over two months to go I am pleased to say that we already have 22 FM stations and 16 SSB stations agreed. We have organised the SSB stations in a different way, wherein we have just placed one SSB station in a Maidenhead Square, whereas we allow at least two or three FM Stations per Maidenhead Square. The SSB stations will all be operating vertically polarised to not burden those stations with…

In many ways, I still like the ‘old’ ways of doing things. For example, listening to weather forecasts on a vintage radio still gives me joy (PW December 2025: 14). And, in terms of getting an idea about prevalent HF propagation conditions (PW January 2026: 52), I often use one of my best-loved shack accessories: The MFJ-890 Beacon Monitor from the (now-defunct) MFJ Enterprises (Fig. 1) is remembered by many simply as the ‘Beacon Clock’. It is linked to the International Beacon Project (IBP) coordinated by the Northern California DX Foundation (NCDXF) (Table 1). With the MFJ-890, users with their radios tuned to five particular frequencies (14100, 18110, 21150, 24930, and 28200kHz) can evaluate HF band conditions every three minutes. Many placed the beacon monitor on top of, or near,…

ARISS NEWS:(from ICQ Podcast) ARISS has released a new video promoting amateur radio on the International Space Station (ISS). Produced by NASA, the video features astronaut Nichole Ayers KJ5GWI aboard the ISS explaining how amateur radio plays a part in school contacts with astronauts on the ISS. Ayers explains many of the procedures and technical challenges that amateur radio operators must address during a school contact. “It’s a true privilege for me to be able to inspire the new generation of scientists and engineers through amateur radio.” www.ariss.org In related news, the first HamTV transmission from the International Space Station (ISS) since 2018 occurred on 18 October 2025. As part of an ISS contact with the 1st Radford Semele Scout Group in the UK, HamTV was utilised in addition to…

Welcome to the February HF Highlights. Once again, the sun was very active during the month under review. On 6 December the solar flux was at 206 units while the sunspot number rose to 131 by 8 December, caused largely by the massive sunspot complex shown in Fig. 1. The Spaceweather website commented: “If there’s no X-flare this weekend, it will be a waste of a truly monstrous sunspot… Even Richard Carrington would be impressed” (Carrington being the 19th century British astronomer after whom the ‘Carrington Event’, the most intense geomagnetic storm in recorded history, was named). spaceweather.com In the November 2025 column I speculated that solar cycle 25 might have two peaks. It now seems that the first peak has already occurred, probably in October 2025. In the ARRL Solar Update…

In October 2025 I gave a presentation at the RSGB Convention in Milton Keynes describing a holiday-style DXpedition to Lanzarote I made in September 2024. Several people in the audience asked that I do a write-up, hence this What Next – a condensed version of my presentation. Much of this What Next might also be of interest to POTA and SOTA etc. activators. Holiday-style? For me, a holiday-style DXpedition contains elements of a holiday and a DXpedition. It might be termed a light-touch DXpedition - operating interspersed with holiday activities such as sightseeing, walks, swims etc. Others no doubt take a different view and perhaps tack on some operating in the evening to a normal family holiday for example. Why Lanzarote? I was looking for somewhere that was easy to…

Planning antennas for our next DXpedition was interesting as our trip to ZC4 was going to be limited by weight due to flights as well as the operating style. We are running barefoot and need every antenna advantage that we can get. I decided to build a set of loop antennas for station 2. They give more gain over a dipole and of course they are directional. This could be handy to help deal with local EMC issues or to help with multi-radio RF breakthrough. Unlike my usual self-build loops I had to construct a loop which is light as possible but also so that it was fail proof. Parts needed To build the loop I used: 1 x length of RG6U (75Ω) 1 x PL259 plug 1 x electrical…