Indholdsfortegnelse for April 2025 i Practical Wireless

The highly anticipated Icom IC-PW2 1kW linear amplifier is almost here! A limited first production run was scheduled in Japan for late February, with UK delivery expected in March (subject to confirmation). This powerful linear amplifier will be available at a recommended retail price of £5,375.00 including VAT. Full specifications and details can be found on the IC-PW2 product page. Please note that this initial production run is strictly limited and will be available exclusively from authorised Icom amateur radio dealers. Additionally, the eagerly awaited IC-7760 200W HF/50MHz Transceiver has experienced a slight production delay and wass now expected to be available by late February. Icom UK are also pleased to announce the IC-2730E (Black Screen Edition), a stylish new version of their popular VHF/UHF dual-band FM mobile transceiver. Featuring…

Anytone or rather should I say, Qixiang Electron Science & Technology company Ltd, has been designing and manufacturing communications equipment at its 18-acre factory site in Quanzhoa, Gujan China since 1993. While Anytone is one of its brand names this ISO9001 high tech company makes a wide range of communications equipment, including DMR handportables, marine and land mobile radios and repeaters under various names, exporting them to over 65 countries, at the last count. When asked to take a look at Anytone’s latest offering to the amateur market, its rather sophisticated AT-6666 Pro, I must confess I was a little daunted. Anything with an obvious citizen’s band looking heritage I last encountered back in the crazy boom days of 40 channel, illegal AM and FM in the 1980’s. I made…

The nRSP-ST is the new Software-Defined Receiver (SDR) from SDR market leaders SDRplay in the UK. Its emergence in the fast-changing SDR market follows in the footsteps of the release of, first the RSP1B and second, the RSPdx R2, both of which have received excellent appraisals. As far as I know, the nRSP-ST is the first networked receiver that SDRplay has built. Following some tantalising glimpses at the unit during the 2024 UK National Hamfest in Newark, the new receiver was officially launched in November 2024. A few days earlier, Jon Hudson at SDRplay was kind enough to send me a review unit. In what follows, I would like to share my general findings and thoughts on this latest addition to the ever-growing SDRplay range. However, I admit that I…

My parents drilled the above mantra into me as a young boy and I have always lived by that principle. I feel that there is a distinct lack of living by this principle with some of the modern generation, not all, but a reminder or two never hurt, so I thought it would be a good idea to apply it to operating on the air. We all know of the dreadful behaviour of some in pile-ups, the UP UP UP brigade, the Frequency Police Service, the eloquent exchanges of abusive and foul language and so on. I thought that besides the DX Code of Conduct (that some could still do well by reading!) I would set out a few simple suggestions to new CW operators in the hope that we…

Portable operation has several advantages over fixed, home-station operation. It gets you out into the fresh air and you get to operate at locations that may be better than your home in some circumstances and directions. There are disadvantages of course – having to carry your kit, antennas often at suboptimal heights, often with less power than you might prefer. These of course are generalisations. Some/P locations may provide such easy access as merely driving up in your car and plugging in a previously erected permanent unobtrusive antenna. VHF/UHF beams may be easy enough to transport and erect, but simple wire antennas are the order of the day for HF/P work. Unless of course you can turn your simple wire antenna into a beam – and I’m not talking about…

Members of one of my local clubs recently decided to try a 2m net using Single Sideband, in addition to the existing nets on 2m and 4m FM. A relative newcomer expressed concerns at the potential dilution of activity away from their familiar FM net, even though the new net would be on a different day of the week. I explained that while SSB is by far the most common voice mode on the HF bands (apart from some FM on 10m and an occasional AM QSO on other HF bands) it is also used on the VHF and UHF bands. The newcomer was surprised that SSB is used at all on the VHF and UHF bands. I guess this is understandable as SSB gets little mention in the Foundation…

Despite not mentioning VarAC in a few columns, the development team has been busy adding new features to this increasingly sophisticated keyboard chat mode. At the time of writing, it’s version 10.4.3, and seeing so much effort by the development team to respond to user requests is encouraging. As with all data modes that are not FT8 or 4, locating active stations is half the battle. VarAC approaches this in several ways. At the top of the main screen, Fig. 1, are panels marked Beacons and CQ Calls. The Beacons are typically sent every 15 minutes, indicating online stations but not necessarily those accepting QSOs. In addition to showing the callsigns of received stations, the list has a column marked T∆, which shows the elapsed time since the specified beacon…

On 12 February RigExpert’s administrative office, in Kyiv, Ukraine, was destroyed by a Russian ballistic missile. All employees are reported to be safe. RigExpert is a leading manufacturer of antenna and cable analysers and officials said they are committed to restoring operations as soon as possible. “Our top priority is the safety of our team and the continuity of our operations,” said Ashot Andeev, Chief Executive Officer. “While our administrative office is in ruins, our production facilities survived, allowing us to continue serving our customers and partners.” The company is working to minimize delays and fulfil its commitments while maintaining customer support operations.…

One item which is mostly missing from PW is a VHF power meter, because construction at VHF is not easy, nor is it cheap. This little PCB will solve both those problems. It is claimed to be usable as high in frequency as 600MHz, and a maximum of 5 watts RF in Photo 1. It is available from the usual suspects at under £10 – search Amazon for RF detector module, 1-600 MHz, Ref B07N4N3VTG (currently £10.45) or even cheaper on AliExpress. The attenuators illustrated are BNC and the rest of the rig is SMA. They are shown to illustrate the principle, Photo 2. Likewise, keen-eyed readers will observe that the Quansheng is not transmitting, although the meter has a reading. This is because there is a standing voltage on…

As anyone who knows me knows, I am a sucker for a radio of character that needs a bit – but only a bit – of work. Photo 1 shows an Icom IC290A, a 2m multimode from before I was licensed. It came to the Radio Society of Harrow as part of a large silent key sale. After clean-up – it spent many years in a garden shed – and testing, it was found to be working, but not fully. “It receives fine”, my friend Peter Marcham G3YXZ told me. “And it transmits, but there is no audio”. To be honest, I wasn’t that interested at this point. But when I received the update that with an Icom SM05 desk microphone plugged in the transmit audio was restored, this radio…

Peter Taylor G8BCG emailed to say that he is now custodian of the list of 50MHz ‘firsts’ from the UK and Northern Ireland. Peter writes, “with the recent F2 openings there has been quite a lot of new DX worked. I maintain the UK Firsts List on behalf of the UK Six Metre Group at: www.g8bcg.org.uk/6mukfirsts.htm “These listings are compiled from claims to be the first station to work a particular country on 50MHz from the United Kingdom and Northern Ireland. They are separated into the DXCC ‘entities’ of G, GD, GI, GJ, GM, GU and GW. Please help us keep these lists as up to date and accurate as possible by submitting your claims and updates. “Please send any comments, omissions, corrections or new claims to Peter G8BCG at DXCC-Firsts@g8bcg.org.uk. Note…

In July 1975 SV1GA/A, operated by Aris SV1GA and Martti OH2BH, was active for six days from Mount Athos, Fig. 1. Almost 50 years later, and beginning on 25 January, the same callsign was used for a surprise operation by Aris and Martti, this time joined by Adrian KO8SCA, Gabi YO8WW and Niko OH2GEK. However, the activity was halted only two days later after questions were raised about whether or not the correct authorisation to allow amateur radio operation had been received. On 29 January OH2BH, quoted on the DX-World website, wrote: “The matter of amateur radio in Mt Athos is in the hands of different entities within the Holy Community… For us the key entity is the authority that issued our invitation/permit to carry out the SV1GA operation. Our…

A home made lightweight yet strong vertically polarised 70MHz quad is described that also works well from 50MHz to the top of the VHF FM band. Unusually for a VHF antenna the quad is fed with 95Ω twin feeder [1]. This makes the whole antenna system very much lighter than one made with coax cable. The antenna also works down to 40MHz (8m band) and so may be a useful ‘get you on the air’ antenna if permission for this band is granted in the future [2]. This is also an interesting antenna to listen to distant FM radio stations, which can be a way of monitoring VHF band conditions. The antenna should also cover the aircraft band. Many quad designs have been published over the years, this version is…

In the course of setting up my new shack – a spare downstairs room – I confronted the question of how to get my aerial feeders into the shack. The scale of the problem is that, ideally, I would like to have between two and four HF aerials available and three VHF/UHF aerials likewise. That amount of thick coax makes quite a substantial hole in the wall necessary, and that was just not going to be desirable – I know some people do it, using plastic drainpipe and expanding foam, but it’s not for me. Also, we have cavity wall insulation using tiny polystyrene balls and I don’t want a waterfall of them coming out when I make such a hole! It did occur to me to bring the cables…

Hello and welcome to this month’s edition of Antennas. Correspondence from readers suggests that there is a great deal interest in the use of Vector Network Analysers. It is notable that a fair proportion comes from readers who have left the hobby and returned after a number of years and are therefore not familiar with these devices. So, this month we will have another look at VNA’s, specifically those based on the popular NanoVNA, and their uses in the amateur radio shack. We will take a look not only at checking antennas, but also filters, antenna traps, and individual components. Getting to grips and understanding how these little analysers work is not only interesting but also educational and dare I say it, fun! Like an oscilloscope can help one to…

Here is a simple little voltage reference circuit that will help you to standardise your test gear: multimeters, oscilloscopes etc, Fig. 1. As a maintenance tool it can help you to find faults and check performance. A voltage reference is a device that provides a fixed output at a precise voltage, usually 5, 7 or 10 Volts. For professional applications it would be calibrated by comparing it to a calibrated reference voltage traceable to a National Standard. Calibration You will notice that in my opening sentence I said the unit can be used to standardise your equipment rather than calibrate. To be able to calibrate your equipment you would have to send either your meter or voltage reference to an accredited Calibration House where it would be calibrated by comparing…

Send your letters to: Practical Wireless Letters, Warners Group Publications plc West Street, Bourne, Lincs PE10 9PH E-mail: practicalwireless@warnersgroup.co.uk Memories Dear Don, There were a couple of things that you mentioned in the March Keylines that brought back some memories for me. Firstly, your comments about advertisements in magazines like PW. I remember (and I still have a lot of them) electronics magazines from the mid 1970’s where there would be pages of advertisements from shops selling components and test equipment as well as radio equipment. Many of these were based in North London around the Edgware Rd and Tottenham Court Rd. Henry’s Radio and Laskey’s for example. Over the years we’ve had a few shops here in Derby that sold electronic components and equipment, including Maplin and Tandy. These…