Tabla de contenidos para April 2023 en Practical Wireless

The elegant-looking Alano ALK/BEA101/103 kit (‘Bausatz’), for making your own DAB and FM radio, is a low-cost (€39.95/€ 59.95) easy construction project available via Amazon (Germany). Whereas the Alamo 101 is in Mono, the 103 comes in Stereo with a colour display and a PSU. Rudolf Hoffmann has put a 103 together for Radio Kurier (2/2023: 27). The kit does not require any soldering, just plug, screw and play. There is a USB port for MP3 files, an AUX port, a display brightness control, an alarm, remote control, and an equaliser. This nifty and educational kit comes in green, red, orange, yellow, and blue. https://tinyurl.com/2jw4dhbn…

The FTM-500DE shares the Yaesu core features, utilising the latest C4FM Digital technology with many new features and improvements. It offers true dual-band operation, i.e. operation with two active receivers simultaneously. Reception of 2 x VHF or 2 x UHF is also possible (V/U, V/V, U/U). 1000 memories help to organise the most popular frequencies and always have them quickly accessible. The receiver operates continuously from 108 to 1000 MHz and thus also enables reception of aeronautical radio (AM) or marine radio (FM). A special feature of the FTM-500DE is the integrable optional Bluetooth interface BU-2, which enables ‘hands-free’ operation, i.e. the possibility to make radio calls without an annoying microphone cable and without constantly pressing the PTT button, as is now the rule for mobile operation while driving. Yaesu…

The SWLing Post and other radio publications have recently showcased a stylish new docking station, made by Pavel Kraus. Pavel writes: “I made a small docking station for the Belka – it has a built-in stereo amplifier, speakers and a battery with a charging circuit and a DC-DC converter for emergency charging of the Belka in the field. The status of the battery is indicated by LEDs. The Belka holder itself is made on a 3D printer.” https://tinyurl.com/2y94r558 Pavel also makes some very innovative radios: https://tinyurl.com/yjmnupsz…

Practical Wireless Rating Hits the spot for experimentation. Most of you will probably be familiar with the Deepelec brand, probably on account of the nanoVNA antenna analysers used by many amateur radio operators, hobbyists, makers and experimenters. The firm behind it is the Chinese manufacturer Hangzhou Minghong Electronic Technology, Ltd. https://deepelec.com/en I had read about the nanoVNA, and I am interested in smaller SDR receivers, hybrids and general radio innovations, Some time ago, I reviewed the ATS20 and ATS-25 SI4732-chip receivers for RadioUser (December 2021; February 2022) and found them very versatile indeed. In terms of those SI4732 receivers, the newer, slim-line, ATS100 mini-SDR appears to be the most comparable radio to the DeepSDR 101, which is under review here. Therefore, I was curious and took note when I heard…

Staying with the construction theme this month I thought I would explain how I have recently implemented 13.8V power distribution in the shack. For the last few years my shack has been located on the ground floor of the house in a compact ‘snug’ type area off our sitting room. Given it was compact, most of the rig wiring and other accessories that use 13.8V went directly to the rear of one of two PSUs where, using crimped and soldered ring terminals, they were attached to the rear binding posts. There were a couple of issues with this. If you wanted to remove a power lead, you had to delicately pull the PSU forward, often under cable tension, and remove just about everything to get at the lead you wanted…

My friend Paul VK6EMD had recently purchased a Yaesu FT-891 for mobile and portable use. He gave me a call and we started to talk about the connections for CAT control and for doing data modulation. It was at this point I released that Yaesu installed a USB-B connection purely for CAT control and that there was no in-built sound card, which is needed for data mode modulation. With such a modern rig I personally felt this was a let down by Yaesu but nonetheless I wanted to help Paul so that he could enjoy data modes. I looked at the available connections from the manual and constructed a simple soundcard interface using the following parts: • 1 x USB 7.1 soundcard • 1 x prototype board • 2 x…

Radio amateurs have been transmitting and receiving television pictures since the late 1940s. However, the techniques used have changed many times since then. Initial transmissions were 405-line black and white; cameras and display monitors were generally homebuilt due to the cost of commercial TV equipment. During the 1970s amateur TV followed the broadcasters and migrated to 625-line pictures with colour following soon after. Initial transmissions used 70cm AM and 3cm FM. As the available bandwidth in 70cm reduced, activity migrated to 23cm FM. This was, in part, enabled by the availability of cheap satellite TV receivers, which could receive the signals directly. As satellite TV has transitioned to digital transmissions, so has amateur TV. Initial experiments used heavy, power-hungry ex-broadcast equipment with modified domestic satellite receivers, but it is now…

It’s hardly surprising that in addition to the familiar QRM and QRN, the Q-code QRH (“What is your wavelength?”) was one of the very first to be defined by the International Radiotelegraph Convention of 1912. Radio amateurs are so well aware that DX propagation is closely linked with operating wavelength that it may seem strange that when Marconi first spanned the Atlantic on 12 December 1901 he had very little idea of what frequency he was using. Later analysis of what could be deduced about the antenna and circuit constants of his 15kW spark transmitting station at Poldhu suggests that it probably had a fundamental resonant frequency of around 820kHz. However, the path attenuation at that frequency during the daylight hours at a sunspot minimum would have been very high.…

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Practical Wireless Rating Excellent value & fun to build I purchased the ASCEL Electronic AE20401 Frequency Counter/Power Meter as a kit directly from the manufacturer in Germany in June 2020. Due to an over-indulgence in electronics kit purchases in 2020/21, it remained in storage until 2023, when I rediscovered the kit parts while setting up my radio workshop at home. I can’t remember exactly where I first came across ASCEL Electronics, but I have checked and they are still manufacturing the kit as well as other test instruments in kit form. I will provide further details at the end. Very briefly, using the manufacturer’s own explanation, highlights of its capabilities are as follows: • The AE20401 combines three different functions: • A frequency counter measuring up to 5.8GHz with the…

It is pretty clear that both in the UK and the USA, OFCOM and the FCC are dead against giving access to 8m as a band in the Amateur Radio Service. They even seem reluctant in the USA to grant permits to carry out genuine research. Approvals have to be vetted by the military and they want to keep access to these frequencies as clear as possible perhaps? The Official Secrets Act or its equivalent in the USA is preventing the whole truth being made clear to those who want to know. It is not just that authorities are neutral: the distinct impression is they are dead set against even a tiny, narrow, digital only, secondary, amateur band despite the case being overwhelming. No doubt those who know are frightened…

In the February 2023 issue of PW I reviewed the useful little Two Port VNA-3G Vector Network Analyser (VNA), which was kindly provided for review by Martin Lynch and Sons. It covers the frequency range of 50kHz to 3GHz, undertakes S11 and S21 measurements and also has a handy in-built signal generator. Reviewing modern equipment, whether it be a top of the range transceiver or a ‘gadget’ such as the VNA-3G, while always enjoyable, can be difficult. This is because most of today’s equipment has so many features so much has to be left out in a short magazine review and the VNA-3G was no exception. So, I thought that this month I would run over a number of basic S22 Two Port Through measurements that were made during the…

• THE FACE BEHIND THE CALL: Roger Dowling G3NKH goes behind the scenes with Paul Heiney, well known from That’s Life and elsewhere. • DOUBLE TURN MAGNETIC LOOP FOR LF BANDS: Maurice Webb GW0UGQ returns to the fray, this time with a double-turn magnetic loop. • A FIELD STRENGTH METER REVIEWED: Dr Colyn Baillie-Searle GD4EIP reviews the latest offering from Kanga Kits. • TRAP THAT COAX: Billy McFarland GM6DX takes readers through the design and building of coaxial traps for multiband antennas. • CARNARVON REVISITED: For this month’s Valve & Vintage outing, John Rowlands MW1CFN takes us to Marconi’s Carnarvon station. • AIRCRAFT RADIO: Joe Chester M1MWD visits the Smithsonian Museum in Washington DC and learns about the development of aircraft communications.…

New from Moonraker Produced by the latest technology, the AnyTone ARES II AM/FM/SSB 10m Transceiver features: FM/AM/SSB mode • Weather Channel 150-170MHz programmable (Optional) • CTCSS/DCS Code(Optional) • PWR, RX RSSI S-Meter • PC programmable • Echo Function • SQ, ASQ Function • RF Gain Adjustment • Mike Gain Adjustment • H/L power • Programmable RB • NB/ANL Function • Offset Function • Beep Voice Prompt • +10KHz Function • TOT Function • HI-CUT Function • Busy channel lock • Monitor • LED Brightness Adjustment • SWR Protection • Voltage Protection Technical Specifications: • Frequency Range: 28.000-29.695MHz(Programmable) • Frequency Band: L band: A/B/C/D/E/F H band: A/B/C/D/E/F • Channels: 40channels(programmable)in each band • Frequency Control: Phase-Locked-Loop Synthesizer • Frequency Tolerance: ± 5.0 ppm • Input Voltage: 13.8V • Microphone: with push-to-talk/UP/DN…

As a digital portable internet radio, the WFR-39 offers a generous memory bank for up to 448 station presets and an App that gives the freedom to control your radio from anywhere under the same network. Featuring the weather and financial information, you get to wake up with the weather and financial updates right off the back! The customisable menu and radio preference management are just like the icing on the cake making WFR-39 the radio of your choice! • FM-RDS/DAB/Internet Radio • ATS (Auto Tuning System) • Station Presets (99 FM/99 DAB/250 iRadio) • Spotify Connect for Music Streaming • Cloud Music (Podcasts/Amazon Music/Deezer/Napster/Qobuz/TIDAL) • Media Centre Supporting UPnP • Mobile App (AirMusic Control) • Built-In High-Quality Speaker • Scheduled Playing • Sleep Timers • NAP Alarm • Adjustable…

The MFJ-1708B-SDR is produced in three versions: with PL connectors, with N connectors, and with an SMA connector on the SDR side. This MFJ accessory allows the simultaneous use of the external antenna between your SDR receiver and a transceiver. When transmitting with the transceiver, the switch disconnects the SDR to prevent it from burning out. This is the typical configuration, but you can actually connect a second transceiver to the receiver connector, but the important thing is not to go to transmit. The splitter provides a high level of isolation between the transceiver and SDR receiver input to reduce crosstalk and interference between the two inputs. The dedicated input for the SDR receiver has a prevention circuit to protect against damage due to the transceiver’s radio frequency. The receiver…

Practical Wireless Rating Great ‘play value’ for portable work. Family holidays, or simply out for the day operating/P, whatever you’re up to radio gear always needs an effective antenna. When travelling, antennas may have to pack into a small space among many other mundane items of much less important personal or family luggage. Perhaps there are size limitations on what you can stash or, for a dozen other reasons, weight is at a premium. Having previously arrived at locations where the brochure photograph hasn’t quite lived up to the holiday reality, I soon learned that you need to pack more than one antenna solution. I’ve discovered, for example, overhead power lines air brushed out of photographs more than once. At one location I intended to strap a vertical mast to…

If it’s Saturday it must be….in this case Orlando, Florida. At the HamCation. Not just Hamfest anymore. Why does that word just seem so appropriate here, yet jars a bit back home? The New World. Of new language. And perhaps it’s an appropriate term. Orlando is another word for theme park. A holiday destination. And HamCation is huge – just enormous. Acres of space, four large indoor spaces, and the outside acres covered in radio equipped RVs and camper vans. It’s a 15-minute walk to get from the halls to the presentation space. This is the third in an occasional series. It started in Newark, before Covid, then Friedrichshafen last year, and now Orlando. Leave the big one (Dayton) for another trip. And the first thing to say about Orlando…

Welcome to the April HF Highlights. On 16 January the solar flux peaked at 234 sfu and on 20 January the sunspot number was briefly as high as 207. These are the sort of figures that, if sustained, can provide worldwide and long-path openings on 28MHz and F2 propagation on 50MHz. Unfortunately, both measures decreased quite rapidly and by 3 February were only at 134 and 54 respectively. Nevertheless, on 2 February the Spaceweather website reported that the monthly sunspot count in January had been at a nine-year high, very close indeed to the peak of the previous solar cycle in 2014. Fig. 1, from the US National Oceanic and Atmospheric Administration, NOAA, shows that the number of sunspots recorded continues to be well above the predicted values for the…

It is a long time since I’ve seen a new approach to training for the Foundation Exam. John Hislop G7OHO has produced an excellent training manual aimed at an audience of 12-year-olds and above, Fig. 2. John originally intended the book for a girls’ STEM club, and he developed it in conjunction with his STEAMettes. They call themselves the STEAMettes because they like science, technology, engineering, art and mathematics. The book contains 56 activities and over 200 open (not multiple choice) questions and nine mind-maps. It can be found on the Hilderstone Radio Society’s website at: www.g0hrs.org/g7oho-training-manuals I think the best way to illustrate how different John’s approach is, is to quote an example from the book. I happened to land on the introduction to matching on page 35. This…

Nick Bennett 2E0FGQ posed an interesting question following a QSO we had on 2m FT8. He wrote, “Towards the end of our QSO the WSJT-X software had already popped up the log QSO box and I had clicked that, but your final RR73 was in the process of being received. I never got that, but the logging laptop (over the network) had already accepted it as a QSO. In effect, we had exchanged signal reports and callsigns, so from my point of view it was a genuine contact. However, I suspect that from your perspective, it was not completed if the software didn’t receive my RR. It could be that there are many one-way QSOs like this (due to signal strength suddenly dropping) where one party logs it and the…

Designers have, from time to time, produced receivers of the so-called “midget” type, but these have been in the majority of cases a compromise; We have set out to design an efficient receiver, which could be housed in a really small cabinet, and yet would give really first-class results - giving, for instance, the choice of several stations on the loudspeaker. The photographs and illustrations will give some idea of the compactness of this set, and it will be seen that there is no waste of space in any direction, and the set can justly be called “a midget.” The Circuit The circuit is clearly shown, and it will be seen to employ the usual three-valve arrangement of S.G. detector and pentode valves. The tuner is an ingenious “all-in” device,…