Tabla de contenidos para February 2023 en Practical Wireless

gw4vxe@icloud.com I wrote last month about apparent activity on VHF/UHF with a move away from lengthy voice conversations, something which I suspect affects amateur radio as a whole. As I pointed out this is something that is reflected in our use of mobile phones. More messaging, less talking. I think we can probably see this as a social trend, rather than anything affecting amateur radio in general. I appreciated Ron G4LMN’s letter in the January PW – Ron prefers short QSOs to lengthy ones and doesn’t feel he’s missing out. Quite so. We should all operate the modes we enjoy and certainly not give way to those who would tell us that one type of QSO is more worthy than another! We’re all different and the hobby’s breadth is one…

roger@g3ldi.co.uk It was very enjoyable to see lots of people at the RSGB Convention we had not seen for nearly three years! Hopefully things are gradually getting back to normal again now we are all fully jabbed! Locally the Bootcamps have started again. I received a report from Andy G0IBN from the Essex CW Club and they had a very successful day in a local village hall with several tables all quite full. This is what Andy had to say about it: “Did you miss it? What a shame! Essex CW ARC’s Boot Camp participants had a great day at their annual convention of CW enthusiasts. Some must have been masochists as they had returned for more punishment! “Receiving and transmitting skills were analysed by the instructors and constructive…

wiessala@hotmail.com In this article, I am looking at both larger magnetic loop aerials and smaller ferrite rod/bar aerials. The latter type are also known as ‘loop-sticks’, especially in the USA and Continental Europe. This is, arguably, the most accurate description. The two types of magnetic aerial work in a similar way, with the one difference being that ferrite bars are often much more compact in their dimensions; they are frequently mounted on the inside of smaller devices. This is because the copper loop, in the case of the ferrite bar aerial, is wrapped around the bar, instead of being out on view. Therefore, a loop such as the new Wellbrook ALA 1530LN is often simply called an ‘air-core receiving loop’ (e.g. ARRL, 1997, Ch. 5; 5-8). It is well known…

practicalwireless@warnersgroup.co.uk Since early April, a Test and Innovation licence from OFCOM that costs £50 annually has been held covering 40-42MHz, digital only, with 5W allowed (in practice I use 2.5W). The rig is a modified FT-817ND, Fig. 1, with a low wire dipole, Fig. 2. Mostly FT8 is used as this only needs a transmit bandwidth of about 50Hz. The software (WSJT-X) is free. It is not uncommon on other bands to see 25 stations, or more, co-existing in the narrow FT8 slots. If activity on SSB on other bands looks quiet, then try the FT8 segment! Progress in 2022 So far, the 2.5W FT8 signal has been spotted in 16 countries and 3 continents with the furthermost being Florida in the USA. With a higher ERP, some have reached…

THE YAESU FT-710 AESS: Richard Constantine G3UGF gets his hands on this recently-released transceiver. AVOIDING GETTING LOOPY OVER HF LOOPS: Frank Howell K4FMH looks in detail at building and measuring an HF loop antenna. THE FACE BEHIND THE CALL: Roger Dowling G3NKH invites readers to meet a studio engineer who has recorded the world’s top artistes. AIRCRAFT SCATTER ON SHORT WAVE: Nils Schiffhauer DK8OK explores how we can learn from this little-known phenomenon. A DOUBLE TURN MAGNETIC LOOP FOR LF BANDS: Maurice Webb GW0UGQ returns with another loop antenna design. VALVE & VINTAGE: Philip Moss M0PBM is back with a look at the Eddystone 730/4 receiver. There are all your other regular columns too, including HF Highlights, World of VHF, What Next, Antennas and Data Modes as well as your…

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Moonraker is proud to be back and offering some Steepletone products. Moonraker first dealt with this company back in 1972, ‘in the good old CB days’, as some may say. Now the 2nd and 3rd generations of the family are at the helm and are running the business. Two new receivers are now in stock: The Steepletone MBR1051 7-Band Portable and SAB2019 14-Band Portable Receivers. The SAB2019 is advertised with the following features: High Sensitivity Multi-Use World Receiver FM/AIR/MW/SW1-11; PLL Circuit Multi-Uses Rotary control for Volume, Tuning Pre-programable stations; 4.5V DC Input Socket Headphone Socket for private listening (headphones not supplied) Stereo FM through Headphones Seven-section telescopic aerial (53cm) Direct Key Frequency Input LED Back Light; Carrying Strap Powered by 3 x AA Batteries (not supplied) PU Travel Pouch; Colour:…

keith.g4miu@gmail.com The JNC Radio VNA 3G is a compact portable Two Port Vector Network Analyser (VNA) covering the range 50kHz to 3GHz* (see below). It can be used as a standalone unit and also with free PC software, which provides additional functionality. Some of its measurement features are VSWR, LogMag, Phase, Delay, Q Factor, Polar, Linear, Real, Imaginary, Resistance, Reactance and TDR among others. With the VNA-3G a user can undertake tests and measurements on Antennas, Amplifiers, Filters, Attenuators, Duplexers, Diplexers, Cables, Discrete Components and so on. A basic Signal Generator has also been implemented, which works over the frequency range of 50kHz to 4.4GHz thus covering the main amateur bands from LF to 9cm. Above 135MHz output power is ‘adjustable’ with levels of 0, –3, –6, –9dB relative to…

practicalwireless@warnersgroup.co.uk Well, this is my 150th Data Modes column for PW! If I’ve counted correctly, the first Data Modes went out in the September 2010 issue. That introductory column detailed the terms used in data modes signals such as telegraph alphabets, serial data and baud rates. Interestingly, The ROS mode was in its infancy in 2010, but it is still with us in a much-evolved form as the VARA-HF modem used to power VarAC. Simon Brown’s World Map As a learning exercise for Visual Studio 2022 and Direct2D graphics, Simon Brown G4ELI has completely rewritten his World Map application. As is typical for Simon, he has generously made the software available to us all free of charge. However, if you use the map or any of his other software, please…

practicalwireless@warnersgroup.co.uk PW has previously described an adaptation of a Band I TV antenna [1] but, since that was 40 years ago, and for an entirely different project, I thought the subject might bear being revisited now. Even though several decades have passed since British broadcasters turned off the last of their Band 1 TV transmitters, some of the old receive antennas are still around; and if you’re lucky enough to find one in a loft (as I did), it could be in surprisingly good condition. Once the cobwebs have been brushed off, and the metalwork given a quick polish, you could have almost everything you need to make an effective beam antenna for the 4m band. Technically, these H-shaped antennas are two-element Yagi arrays, with one driven element and one…

practicalwireless@warnersgroup.co.uk In June 2021, in this series, we looked at a variety of HF antennas with the aim of encouraging people who had never built one before to have a go. In this article I am going to walk you step-by-step through the complete build of an End-Fed Half-Wave (EFHW) antenna, including the essential transformer, in this case a 49:1 transformer. First, let’s start go back to basics and describe what an EFHW is. At its most basic it is an antenna that is designed to a length where it is resonant as a half wave on the lowest frequency you intend to operate, the fundamental frequency. So is a dipole, but instead of being fed in the centre like a dipole, the EFHW is fed, as its name implies,…

bgtaylor@ieee.org Although the Heath Company started producing electronic kits in 1947, and the US manufacturer had sold a crystal controlled three-valve CW transmitter as early as 1952, it was from 1956 that the Heathkit brand name became well known in the world of amateur radio, with the launch of the popular DX-100 transmitter. This was followed in 1959 with the first of the Native Indian Tribes series, the Apache transmitter and Mohawk receiver. All these rigs were vacuum tube designs, for transistors with high performance at HF were expensive at that time. (The retail price of a humble OC45 in mid 1959 was 35/-, about £43 in today’s money). But in March 1960, three years before Eddystone launched the transistorised EC10, and four before National introduced the transistor version of…

VOLUNTEERS NEEDED FOR THE EXAMS AND SYLLABUS REVIEW GROUP (ERSG): The RSGB are looking for additional members for the Exams and Syllabus Review Group (ESRG), formerly known as the Exams Group (EG). Membership of the Group now includes places for club tutors who hold a Full amateur radio licence and have taught the Full Syllabus for at least two years. To make an application or to find out more, email the Examination Standards Committee Chair at: https://esc.chair@rsgb.org.uk Applications should include a brief description of your relevant experience professionally and/or in an amateur radio training capacity. Further information about the group, including its terms of reference and membership, at: https://rsgb.org/esrg RSGB LAUNCHES SCHOOL ZONE: Following the success of University Corner, the RSGB’s online list of universities with amateur radio…

practicalwireless@warnersgroup.co.uk Welcome to the first What Next column of 2023 and a special welcome to previous readers of RadioUser. I’m using the occasion to look at a few things that may have featured in readers’ New Year resolutions starting with the various amateur radio licence exams. Then I’m going to look at source of operation information for various amateur radio equipment. Training Courses Since the pandemic, the range of local amateur radio clubs offering training courses for the various amateur radio exams has reduced. The information on the RSGB website is currently very much out-of-date. For example, the details of my local club showed an old meeting location on the map and out-of-date contact details. Our club secretary had to get the RSGB to ‘raise a ticket’ to get the…

keith.g4miu@gmail.com A Vector Network Analyser (VNA) is a versatile tool for anyone who is interested in the design, measurement and testing of RF ‘Networks’. They are used to characterise the performance of RF systems and components that include, but are not limited to, antennas, tuned circuits, inductors, capacitors etc. With a VNA magnitude and phase are measured independently and the results are combined to calculate the impedance of the network being measured. They will also measure insertion loss, return loss and S-parameters, and are very useful when used in the development, testing and manufacture of most things RF. A VNA almost enables the user to ‘see’ into an RF circuit, much the same as an oscilloscope is used to see into an electrical circuit. Something that has held back the…

29 January LINCOLN SHORTWAVE CLUB WINTER RADIO RALLY: The Festival Hall, Caistor Road, Market Rasen, LN8 3HT. Doors open at 10 am with disabled visitors gaining access at 9.30 am. Indoor event. Refreshments will be available on-site. Entry £2 Talk In is on 145.375MHz. contact@m1dhv.co.uk Steve G6TVP/M5ZZZ 07777 699 069 m5zzz@outlook.com 5 February CANVEY RALLY (SOUTH ESSEX AM-ATEUR RADIO SOCIETY (SEARS)): Cornelius Vermuyden School, Dinant Avenue, Canvey, Essex, SS8 9QS. Open 10am, entrance fee is £4 The rally is expected to be the usual hive of activity (CBS [Indoors] | CR | TS). sears.enquiries@gmail.com 07748 432026 12 February RADIOACTIVE FAIR 2023 (MID CHESHIRE ARS): Nantwich Civic Hall, Market Street, Nantwich, Cheshire, CW5 5DG. 100 Traders and Exhibitors Stands. Public transport is onsite, Doors open at 10 am, and admission is…