Índice para March 2022 em Practical Wireless

ML&S take on SteppIR Since 2001, SteppIR Communication Systems has manufactured thousands of mechanically adjusted, remotely tuned, frequency optimised HF/VHF Yagi, Vertical and Dipole antenna systems for Commercial, Amateur, Military, Emergency Communications and Consumer Markets. In December 2021, SteppIR appointed Martin Lynch & Sons to retail & distribute their range of antenna products. For more information see: HamRadio.co.uk/steppIR John Mertel WA7IR, SteppIR President & CEO commented “Martin Lynch & Sons represents a significant step forward for SteppIR Communication Systems. Never before have we had such a well-known, highly respected ham radio reseller as a partner, to assist in the overseas sales, service and maintenance of SteppIR products. It takes a serious commitment to offer the kind of customer service we expect at SteppIR, and we believe ML&S is up to the…

Review The Yaesu FTM-6000E Richard Constantine G3UGF finds the Yaesu FTM-6000E to be “Easy to Operate yet feature packed”. Richard Constantine G3UGF practicalwireless@warnersgroup.co.uk As manufacturers re-style and add features to their radios so as to move up-market, their aim is often to enhance the product offer and hopefully leapfrog the competition. The downside is that they open the market up to others, at the more price competitive end of the market. Yaesu, having spent recent years enticing us to use C4FM Fusion and WIRES-X, recently introduced a new FM-only mobile radio, but why? The answer must simply be, because they can. A number of Far Eastern manufacturers have lately emerged on territory traditional occupied by the big three names. The newly released FTM-6000 series is surely Yaesu’s response. I say,…

Data Modes G4WJS – Silent Key Mike Richards G4WNC reports the passing of a key member of the WSJT team before going on to further advice about using SDR-Console. Mike Richards G4WNC practicalwireless@warnersgroup.co.uk December 2021 saw the sudden and unexpected passing of Bill Somerville G4WJS. Bill was a vital member of the award-winning core WSJT-X development team that comprised Joe Taylor K1JT, Steve Franke K9AN and Bill. Joe Taylor reported that Bill was the first to join him back in 2013 when he formed the core development team for the WSJT-X project that has had such a wide-ranging influence on today’s data modes operations. In addition to his skills as a C++ systems developer, Bill spent countless hours answering questions and patiently helping fellow amateurs with WSJT-X related issues. Bill…

Practical Valved Radio Repair (Part I) Bernard Nock G4BXD embarks on a new series explaining the ins and outs of repairing valved radios. Bernard Nock G4BXD military1944@aol.com I often get asked “how does one repair a valved radio?” It’s a tricky question to answer as there are many types of valved sets, some simple, some quite complicated. There is a basic method though that will work on any set. How complex a set you can fix depends on how deep you want to delve into the art of valves and their circuits. Hopefully I can give a few basic pointers as to how to at least start on your valve odyssey, the sort of tools needed, suitable equipment that makes life easier and the basics of a standard valved radio…

Practical Building the Audio Board Mark Tuttle G0TMT starts construction of the Paston by tackling the audio board. Mark Tuttle G0TMT g0tmt@theshack.org.uk Starting with the audio board might seem like an odd choice as it’s the last section of the receiver. However, there’s method in my madness. Firstly, it’s the simplest section to construct and test. Secondly, I aim to introduce Manhattan construction techniques to unfamiliar readers and finally, the audio board is a free-standing audio amplifier and CW filter, which can be used with any rig. You can use the headphone audio output of your shack HF rig with its volume set very low to test the audio board. You will be able to experiment with the bandwidth and centre frequency controls and how they affect the audio output.…

Next Month in the UK’s best & only independent amateur radio magazine… BUILD THE PW PASTON, PART 3: Mark Tuttle G0TMT moves this month on to the VFO board of the 40m transceiver project. VALVE & VINTAGE: Philip Moss takes a look at the Hallicrafters S20R Sky Champion Communications receiver. HOW TO CHECK PROPAGATION USING FT8: James Stevens M0JCQ explains how to use FT8 as an aid to understanding propagation and chasing DX. USING THE NANOVNA AS AN ANTENNA ANALYSER: The NanoVNA costs a fraction of the amount of even the cheapest antenna analyser. Although it’s a bit fiddly to do so, Steve Telenius-Lowe PJ4DX explains how this diminutive device can be used to measure an antenna’s SWR. There are all your other regular columns too, including HF Highlights, World…

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Feature Single Band Operation In the third part of this project, Dr Samuel Ritchie EI9FZB turns to the 40m band to put the product detector to the test. Dr Samuel Ritchie EI9FZB samuel.ritchie.8@gmail.com In this third part, I have a look at using the quadrature product detector (QPD) described in the January 2022 edition for use across the 40m band. I have chosen this band as it covers amateur radio, broadcast services and occasionally other users can be heard. Block Diagram This article covers two elements shown in Fig. 1; the bandpass filter (BFO) shown in red, and the voltage-controlled oscillator (VCO) shown in blue, which is used to tune across the band. Buy a Filter or Build a Kit QRP Labs supplies a kit for a double-tuned circuit (~$5)…

Feature The Royal Signals Museum Geoff Budden G3WZP reports on recent developments at the Royal Signals Museum. Geoff Budden G3WZP geoffg3wzp@gmail.com The Royal Signals Museum is based at the home of the Royal Signals in Blandford Camp, Dorset, and has an active Outreach Team that takes the museum to many venues and events throughout the region. Pre-Covid the team had a busy schedule throughout the Spring and Summer months visiting schools, county shows, university open days and the five-day Chalke Valley History Festival, the latter attended by school groups and the general public. Practical Activities The emphasis has always been offering ‘hands on’, practical activities to participants to show the development of communications not only in the military but also in the wider world. Morse code is always popular with…

Practical A Pocket Portable 2m Beam Antenna David Johnson G4DHF describes and easy to build antenna that’s ideal for portable operation. David Johnson G4DHF practicalwireless@warnersgroup.co.uk The prospect of returning to the hills and islands around our coast and possibly coupling into sea ducts and Sporadic E openings on 2m, where distances over many hundreds of miles are possible with simple equipment, has always been appealing. The aim was to build a simple 144MHz antenna that provided some forward gain and was small enough to be carried in a pocket. By doing away with metal rod elements and fittings, the whole antenna could be folded into a small pouch, making it ideal for travelling light. Such an antenna would also have potential for stealth, SOTA or holiday travel. Being only a…

Regular FM activity Tim Kirby GW4VXE has a first listing of regular UK VHF/UHF nets. Tim Kirby GW4VXE longworthtim@gmail.com Last month, I asked you for details of any regular VHF/UHF net activity so that I could start including a list of nets in the column. My hope is that it may give newcomers (and others) something to listen for on VHF FM at a given time and frequency, rather than switching on, tuning across the band, finding it dead and then switching off again. The response has been excellent. I’m very pleased to be able to include the first version of the list in this month’s column, Table 1. The nets included so far are from people that wrote in response to my request for info last month, along with…

Amateur Radio on a Budget Linear Amplifiers Daimon Tilley G4USI looks at a selection of amplifiers, both HF and VHF, available for budget prices. Daimon Tilley G4USI practicalwireless@warnersgroup.co.uk As we continue to build our budget station, this month I turn my attention to linear amplifiers. But before we get into the meat of this and look at options, we should first consider why we might wish to own such a device. In order to do this we should first of all consider our antennas and our preferred operating modes. Regarding antennas, I would strongly encourage readers to consider whether just pumping more power into their existing antenna is the best way forward. I am going to give an example at VHF frequencies because directional antennas at these frequencies are smaller,…

Practical The Kenwood TL-922 Dr Bruce Taylor HB9ANY describes this potent HF bands linear power amplifier. Dr Bruce Taylor HB9ANY bgtaylor@ieee.org One of the delights of amateur radio is the possibility of making DX contacts on the HF bands with remarkably low transmitter RF power. But when propagation conditions are poor, or interference or QSB is severe, it can be helpful to maintain a quality R5 QSO by switching in a linear amplifier that can run up to the legal limit. Since Kenwood entered the amateur radio market in 1958, the company has earned a reputation for high quality products that are built to last. Although the first TL-922 power amplifiers, Fig. 1, are now well over 40 years old, examples in excellent condition can still be found at swap…

From The Ground Up Semiconductors (Pt III) Following on from part ll, Eric Edwards GW8LJJ looks at some other diodes, starting with Zener Diodes. Eric Edwards GW8LJJ ericgw8ljj@outlook.com The term Zener refers to the reverse conduction of a diode when a certain voltage is reached, called the Zener voltage. Current flowing backwards in a conventional diode can damage it if the applied voltage gets too high and is known as avalanche breakdown. Zener diodes, also known as ‘breakdown diodes’, are designed to reliably allow current to flow backwards without damage when a certain voltage is reached. The current now flowing through the Zener diode increases dramatically to the maximum circuit value, usually limited with a series resistor. When this current is achieved it remains fairly constant over a wide range…

The Faces behind the Calls The Faces behind the Calls Roger Dowling G3NKH meets a couple who are a regular presence on digital radio. Roger Dowling G3NKH practicalwireless@warnersgroup.co.uk It all started with Citizens Band radio. Linda G0YLM, Fig. 1, from Morecambe was persuaded by a friend to get into CB when she was in her late teens. Through CB they both met their husbands – in Linda’s case Manchester-born Ian Maude G0VGS, Fig. 2, who had been involved in CB since 1981. Ian was then going to college with a view to taking the Radio Amateur Examination. Meeting Linda delayed these studies and it was not 1994 that – with the help of local radio amateurs – he successfully took the RAE as an external candidate atTrafford College in 1994.…

Kits and Modules RF Spectrum Analyser and Dummy Loads Geoff Theasby G8BMI covers two very different topics in this month’s column. Geoff Theasby G8BMI geofftheasby@gmail.com For years, a spectrum analyser was an unobtainable item of test equipment for radio amateurs, due to the expense. While less sophisticated units have appeared of late, there hasn’t been one for the experimentally minded to get to grips with. Until now. There have been software versions, operating at audio frequencies, and later, SDR receivers that were capable of operating at real radio frequencies but again restricted by the desktop computer’s limitations. The LTDZ module (eBay and elsewhere) is a genuine RF spectrum analyser, with a tracking generator, even though it does not meet all the claims made for it, but then, it only costs…

Feature The HW-9: Heathkit’s last QRP Classic Ian Liston-Smith G4JQT describes the HW-9, its features and its flaws. Ian Liston-Smith G4JQT ian.ls@hotmail.co.uk Many readers will know of the Heathkit Company, Benton Harbor, Michigan, USA. From the late 1940s to the early 1990s, the company produced a wide range of electronic kits. In the 1970s, Heathkit introduced the first in a series of solid-state HF QRP CW transceivers, the HW-7, supplied between 1972 and 1975. Then came the HW-8 available from 1976 to 1983, which is widely said to be Heathkit’s most popular amateur radio kit and is described with some of the popular basic modifications in my PW article published in November 2015. Heathkit’s final CW QRP kit was the HW-9, offered between 1984 and 1991. It had a superhet…

Review Practical Antenna Models Volume II by ON5AU Keith Rawlings G4MIU recommends a book of particular interest to users of the EZNEC software. Keith Rawlings G4MIU practicalwireless@warnersgroup.co.uk I have previously had the pleasure of describing two of Marcel ON5AU’s antenna modelling books in PW, namely Advanced Antenna Modelling (AAM) and Practical Antenna Models 1 (PAM1). AAM concentrates on the techniques of antenna modelling using EZNEC and also optimising these models using Dan Maquire AC6LA’s application AutoEZ. PAM1 follows up on these techniques in a practical sense and concentrates on the modelling of dipoles and variations of the dipole family. Both of these books have a great deal of work put into them and are very informative, as are the accompanying downloadable files, which consist of completed antenna models that accompany…

Star Letter The Star Letter will receive a voucher worth £20 to spend on items from our Book Store, or other services offered by Practical Wireless HF Signal Generator Dear Don, I would like to record my thanks to Eric GW8LJJ and Practical Wireless for his excellent Signal Generator article in the November edition. I purchased the PCB and some of the components from Eric and built the Generator. It worked first time and performed as described. I subsequently made a couple of modifications which may be of interest to other readers. I added an extra relay with a 200µH inductor to get an extra range covering the medium wave. broadcast band and 455kHz IF. I then changed the 22µH to 47µH to lower to the range of the second…