Tabla de contenidos para June 2023 en Practical Wireless

Not much operating for me this past month, but I did get in some socialising by way of a trip to the Yeovil QRP Convention in Sherborne. I went specifically to see Tim Walford G3PCJ who has promised to write one or more constructional articles, based on some of the kits he sells. I’m very much looking forward to that. But I was pleased to see several other old friends, not least Tex Swann G1TEX, PW’s past Technical Editor, who still lurks in the background tidying up some of the drawings and circuit diagrams for us. Also Colin Redwood G6MXL, he of our What Next column and also our indefatigable contest organiser and adjudicator. And several other occasional contributors, too, as well as plenty of regular readers of PW. All…

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Late last year Martin Moens PJ4MM received a special permit to allow him to operate in the 4m and 8m bands. This unique privilege means that, other than a few VP8 stations in the Falkland Islands, PJ4MM is the only station in the Western Hemisphere to be active on 70MHz. With the 2023 summer Sporadic E (Es) season rapidly approaching, Martin hopes to set a whole series of ‘firsts’ by working UK and other European stations in the 4m band. On an unusually wet and cloudy day (for Bonaire!) in April, I paid a visit to his impressive hilltop house and station, Fig. 1, to find out more about Martin’s hopes for this year’s Es season, and to learn about his future plans for a ‘mega’ VHF/UHF/microwave station. The house…

Although good, propagation was not quite as exceptional in the March-April period as in previous months, as noted by several of our correspondents and confirmed by Neil Clarke G0CAS in his 28MHz beacon report. Neil said that on the 24th and 25th, for example, the only beacon heard was PY4MAB 28270. Paths to North America were good, especially to the East Coast with 4U1UN (New York) 28200 heard on 20 days, though W6WX (California), also on 28200, was heard on only two days. There were no days when beacons in all ten US call areas were heard, although on three days of the month beacons in nine of the call areas were logged. In South America, PY4MAB was logged on 28 days from late morning till into the evening. Looking…

Following last month’s mention of the need to QSY from the calling frequencies, the new VarAC v7.0 makes the process even easier and adds some shiny new improvements. The QSY change adds an automatic QSY mode that’s turned on by default. Previously, a QSY request from one station had to be acknowledged by the other station before it would proceed. The new system still allows the distant operator to cancel the request but, if there is no response, the QSY will occur after a few seconds. The automated process has several applications. First, it will simplify QSYing, which will help new operators relocate away from the calling frequency. Another important application is the sending of large emails or files. These can now be sent to a station using a QSO…

This set, as seen from the front in Fig. 1, I bought from a school friend when I was about 14, for £5, which on my pocket money was quite a lot, though not unreasonable. It came with a battery charger to power it. My radio was the Mk2 version, which unlike the 6V Mk1, ran off 12V. The charger proved more useful than the set to be honest, when I had a car, somewhat later. At the time I was told by him that the set was used in tanks – not true. The closest to a tank is its use in an APC (armoured personnel carrier), FV432. Well they look a bit similar… Mine had an intermittent fault, it would just stop. I did know that when I…

Caister Marconi station contacts more than 150 radio amateurs Radio amateurs at Caister Lifeboat in Norfolk managed to contact more than 150 other radio amateurs on Saturday 22 April when they took part in the annual International Marconi Day (IMD) event to mark the inventor’s birthday. Using the call GB0CMS and a mixture of Morse code, telephony and data (FT8), contacts were made across the UK and Europe. Notable contacts were with other IMD stations at GB0IMD Brean Down in Somerset, where Marconi set a new distance record of 14km (8.7 mi) for wireless transmission over open sea in 1897; GB0MGY, which commemorated the ill-fated RMS Titanic; and GX0MXT in Chelmsford – the home of Marconi’s original factory. The Norfolk Amateur Radio Club (NARC) ran the all-day special event station…

Many Short Wave listeners, DXers and professional travellers have invested in the XHDATA D-808 world band radio, which has attracted several positive reviews over the last two years or so. The D-808 – also marketed in some countries under the RADIOWOW brand – has become a popular shack companion, not least, perhaps, on account of its provision of Single Side Band (SSB; USB and LSB) reception. I too had used the D-808 model before, and we covered the radio, and the use of some potential homemade accessories with it, in previous issues of RadioUser and on the Radio Enthusiast homepage. https://tinyurl.com/3uux7uub The brand-new D-109, Fig. 1, under review here, does not, alas, include SSB reception, focusing instead on HF broadcast coverage. However, it doubles up as a wireless Bluetooth player…

I’d be the first to acknowledge that chasing DX is not every radio amateur’s cup of tea. However, for those who do like to chase DX or would like to try, it is useful to have information about DXpeditions to remote parts of the world. The number of DXpeditions is certainly picking up as international travel returns to normal after the Covid pandemic, together with improvements in propagation on the higher HF bands resulting from increased sunspots (the 11-year sunspot cycle). Even if you’re not into HF DXing, it is worth noting that some DXpeditions operate from comparatively rare locator squares on the VHF/UHF bands – particularly operating on 6m and using EME on other bands. An increasing number of DXpeditions are also taking equipment to operate through satellites, including…

The publishers reserve the right to change content according to circumstances. RogerDowlingG3NKHmeetswriter and broadcaster Paul Heiney M0HWV. Tryingtokeyanolder valve amplifier from a modern rig? Billy McFarland GM6DX offers a solution. JoeChesterM1MWDstartsa new series, looking at US Preppers and what they have to teach us about off-grid operating. RayHowesG4OWYan established stamp dealer, recommends chasing amateur radio stamps as a relaxing alternative to DX chasing! TonySmithG4FAIrelatesa little-known tale from World War II, with details of the communications used. MichaelJonesGW7BBYGB2MOPoffers a solution. There are all your other regular columns too, including HF Highlights, World of VHF, Antennas, Book Reviews, Vintage TV & Radio and Data Modes as well as your Letters, the latest News and more…

Ten years ago I decided to design two HF VSWR meters, one with an LCD and the second with an LED bargraph display. With those projects printed circuit boards were manufactured for the sense head and the micro-controller board, which drove the displays. They were successfully built and one meter I have always run with my HF rigs from the shack. I was asked to consider designing a simple HF audio VSWR meter, and it took me a year or two to actually get around to this project. This design is built around an Amicus development board, which is the PIC version of the Arduino. Programmed in BASIC rather than the Arduino, which is generally programmed in C. Of the original boards I had one pair of PCBs left and…

The international electronics group Rohde & Schwarz has been working with research partners to develop the L-Band Digital Aeronautical Communications System (LDACS), a new air traffic control (ATC) communications system that significantly increases bandwidth and allows modern IP-based communications. It is poised to replace the current VHF digital link (VDL) mode 2 in civil aviation to become the future worldwide standard. The frequencies allocated are in the 1452-1492MHz range within the L-Band. LDACS offers data throughput that is up to about 200 times faster than VDL mode 2. LDACS specifically uses portions of the L-Band frequency reserved for flight communications. Modern aviation demands the secure exchange of data and LDACS reliably enables high data throughput that is secured with encryption. With ever-increasing flights, air traffic controllers need to be able…

I am pleased to announce that we have a new GB2CW volunteer. Michael GM5AUG will be using GB2CW on 80m and also 2m FM on two evenings per week. This is pleasing news and helps make up for the losses that we have suffered over the last couple of years. The losses were mainly due to lack of students, but that situation seems to be reversing with more students coming along and the interest in Morse increasing. I think the fascination with FT8 is waning somewhat now with the improvement in propagation and more activity happening using the legacy modes, especially CW. With this in mind it might bring about an increase in Bootcamps too. Michael intends to run one up in the Glasgow area so hopefully that situation will…

The popular Practical Wireless 144MHz QRP Contest is the ideal way for newcomers to the VHF bands and contesting to get a good feel for many aspects of amateur radio contests. It is an excellent way to experience the thrill of making contacts over many km on the 2m band. This year the duration has been reduced by one hour at the request of many of last year’s entrants. Power The power limit will again be 5 Watts at the transmitter so that participants with all types of UK licence can participate equally. Equipment The only equipment you’ll need is a low-power 2m transceiver and an antenna. While you can expect to make some contacts with a basic 2m FM handheld transceiver, most of the activity is likely to take…

Send your letters to: Practical Wireless Letters, Warners Group Publications plc West Street, Bourne, Lincs PE10 9PH E-mail: practicalwireless@warnersgroup.co.uk The 8m ‘Band’ Dear Don, Many thanks for a great magazine and the absorption of RadioUser, which has made it even better. I would like to comment on the letter from Ben Nock in the last edition. I fully support his comments and would like to add the following. I do not see that having access to 8m will teach us a great deal as it is situated between 10m and 6m. We can follow the MUF from 10 to 6 to 4 and then to 2 if we want. What extra help is access to 8m? I am concerned that due to the lack of use of some of our…