Indholdsfortegnelse for May 2025 i Practical Wireless

Over the years I’ve used, owned and reviewed quite a few Icom radios. When project X60 was announced, celebrating the company’s 60th anniversary I couldn’t wait to get my hands on it, whatever it was to be. Always innovative, always a little different and with their own house style Inoue Communications later to become Icom for short, has always stood out from the crowd. Much loved in the past by SSB/VHF B Class licence holders. Remember their amazing little 2m IC-202 SSB portable? The FM IC-2E handheld and IC22A mobile when repeaters arrived… did you own one? The ubiquitous IC-7300 changed amateur radio forever. A one box fully fledged SDR with a great touchscreen menu system was a leap into a new era. One that’s certainly paid off big time.…

BBC coronations: Part XXV As soon as the date for the Coronation of Her Majesty Queen Elizabeth II was known, detailed planning was undertaken by the BBC for radio and television coverage. The historic event on 2 June 1953, was broadcast by the five existing high-power television transmitters located at Kirk o’ Shotts, Holme Moss, Sutton Coldfield, Wenvoe and Alexandra Palace, together with three low-power outlets situated near Newcastle, Belfast, and Brighton. Plans were also agreed with France, the Netherlands and West Germany for relaying the programme in those countries. The vision signal was taken in three centimetric-wave hops from London to Swingate, near Dover, and from there it was re-transmitted across the Channel and received at a point near Cap Blanc Nez. From here, another centimetric-wave link conveyed the…

This month in the shack, I’ve been diving deep into the versatile SATSAGEN tracking spectrum analyser project. I thought sharing my learning experiences with you might be helpful. For anyone attempting any form of RF home construction, having access to a spectrum analyser is a big help. SATSAGEN is a free Windows application generously written and made available by Alberto IU1KVL. The software has been under constant development over the past few years and has become a powerful instrument. Running SATSAGEN with the Analog Devices Pluto SDR works well. However, the lowest supported frequency is 70MHz, so it misses all the lower bands. Thanks to more development work by Alberto, SATSAGEN now supports several expansion options that allow access to the HF bands and below. The most helpful application within…

One of the topics I cowered last month was ‘Port Extensions’. This is where the VNA electrically moves the position of the reference plane after it has been set by a user calibration. For an example, I explained that adding an adaptor to the end of a cable that has had a calibration made to it will move the measurement/reference plane away from the calibration point by the length of the adaptor. This may just be a matter of a few millimetres and on low frequency measurements this ‘error’ will most likely be negligible. However, as we go higher in frequency these few millimetres begin to affect the quality of the measurement. Remember that, with respect to wavelength, the shorter the wavelength, the more the error will be. To demonstrate…

Dave Ackrill G0DJA has proposed that the next of the increasingly popular ‘433 Alive’ events will take place on Sunday 25 May between 1200 and 1500 local time. If you are interested in reading more details about the event, you can find a Facebook group dedicated to it – search for ‘433 Alive’. If you are active on 70cm FM, do have a tune around the FM channels while the event is taking place and you may well be surprised what you can hear. There should be a number of well-sited stations active – and let’s hope that the weather will be conducive to portable operation – so hopefully some exciting contacts will be possible. Photos and reports of your activity will be very welcome indeed. Of course, you don’t…

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Before I go any further with this description of my endeavours with the 2m band, I think I should point something out. As I touched on in part one, I never really experimented with the VHF and UHF bands as much as I could, or should, have. The truth is, I played around at the edges, lost interest, found other distractions in life or didn’t have enough disposable cash, and then picked things up again in 2015, albeit it was with HF. What this means is, I am effectively starting from scratch with the more esoteric aspects of VHF operating, and doing things that some readers may have done 40+ years ago. This will likely result in some ‘wow - I didn’t realise that’ moments. So now you know; I…

There’s a lot of HF news this month, so I’m grateful to editor Don G3XTT for finding an extra page for the column. We start with news of the King’s Baton Relay, a Commonwealth-wide event which started on 10 March. The 2026 Commonwealth Games will take place in Glasgow from 23 July to 2 August next year. The King’s Baton, with a message from His Majesty King Charles III for the people of the Commonwealth, started from Buckingham Palace and will travel to all countries and territories taking part in the Games. To celebrate the King’s Baton Relay, special event station GB1KBR was active from Scotland on HF using CW, SSB and digital modes during March. John Dundas GM0OPS, posting on the CDXC members’ email reflector, said that “Glasgow 2026…

The equipment currently in use for Morse (CW) demonstrations and by museum attendees was originally used by the Royal Signals for training radio operators and consists of two 19in racks (heavy! and mains powered) together with operator boxes connected by long 5-way cables to each pair of operators. This enabled each pair of operators to send and receive Morse code to each other. However, the system suffered from a number of drawbacks: • No provision for instructor to monitor or send CW to each pair of operators. • Earphones were a mismatch of different types some of which were ex language school with microphones. • Long leads were prone to pick up extraneous noise. In fact, when the museum outreach team used the gear at Taunton School system users could…

I’ve usually located my radio antennas, DAB and shortwave, in the loft with the shortwave antenna at the roof apex. The shortwave antenna picks up noise carried on the mains wiring and probably from the computer network cables, one of which runs through the loft space. The antenna also picks up noise from our neighbour’s property but this seems like white noise and not obviously PLT type interference. For the last decade or so I’ve used a commercial wideband dipole that I bought from Nevada and that replaced a homebrew cage dipole. The cage dipole design came from Shortwave Antenna Course created by Jim Vastenhoud who held various roles at Radio Nederland back in the 1970s. I tried using an external ‘stealth’ longwire antenna hidden behind some garden trellis. I…

GETTING STARTED WITH AMATEUR SATELLITES: Tim Kirby GW4VXE explains how starting with amateur satellites need not be difficult. FAULT-FINDING TEKTRONIX OSCILLOSCOPES 465/465B/475 (pt 2): Michael Jones GW7BBY/GB2MOP completes his look at these useful oscilloscopes. ONE ANTENNA AND MANY RECEIVERS: Dr Samuel Ritchie demonstrates how he rolled his own distribution amplifier which is useful all the way to 500MHz. PHASORS TUTORIAL: Jeff returns to explain to Natalie the ins and outs of phasors. USING MMANA-GAL TO DESIGN AN END-FED CFR DIPOLE: John McDonald G8PJC discusses how to design your own end-fed CFR dipole. CHAOTIC OSCILLATORS: Mark Foreman G7LSZ /SA6BID has a novel look at some strange oscillators. There are all your other regular columns too, including HF Highlights, World of VHF, Antennas, The Face Behind the Call, Vintage TV & Radio…

Enhance your IC-7760 experience To coincide with the recent firmware update for the IC-7760 HF/50 MHz Transceiver, which now lets you operate your HF station remotely over the internet or your home network, Icom UK are pleased to announce details of the RC-7760. The RC-7760 is an optional additional controller for the IC-7760 HF/50MHz Transceiver which expands the operational possibilities of your IC-7760, allowing for multi-location control of a single RF deck. The optional RC-7760 controller is identical to the one supplied with the IC-7760 and ensures seamless operation and a familiar user experience. It’s designed for amateur radio enthusiasts who desire convenient control from multiple locations within their home or shack. Together with the IC-7760 firmware update, the RC-7760 provides greater possibilities for your setup. The RC-7760 itself offers…

In this article I look at modifying a professional piece of equipment from the audio-visual industry for use in distributing signals around the radio shack. One of the challenges in the audio-visual industry is the requirement to distribute one or more signals, simultaneously to monitors, recorders, editing desks etc. The equipment used for this specific task are called distribution amplifiers. As in many areas, the audio-visual world is moving from analogue to digital. To our advantage, a lot of the analogue equipment is appearing on the second-hand market. One example is the Kramer Model VM-1411, which is a dual-mode distribution amplifier. This unit has promise as its specifications are: • Maximum output 1.8V pk-pk• Video Bandwidth (-3dB): 240MHz• Video S/N ratio: 77dB• Controls: Trimmers for video gain and EQ• Coupling:…

There can’t be many radio amateurs who cheerfully admit to starting life in prison – but this is certainly true of Jenny Bailey G0VQH, Fig. 1, the subject of this month’s feature. But it was clearly no handicap in life, as in later years Jenny went on to become mayor of Cambridge, about which we will learn more later. Early days I should hastily add that Jenny did not in fact take to crime from a very early age: in fact, her father was a prison officer at Doncaster gaol. “My mother and my sister tell me that it was a very happy time with a great community and lots of parties,” Jenny told me. “The prisoners did a lot of the maintenance and gardening.” Jenny had another unusual start…

Used in conjunction with a communications receiver, either of these converters will give VHF reception, bringing in amateur and other transmissions and in some cases TV sound programmes, using only a simple dipole aerial. The simpler converter is tunable and the more complex converter is crystal controlled, so a few notes on the advantages and limitations of each method should prove helpful. Tunable Converter This is relatively simple, inexpensive and can be used over a wide band by adjusting the pre-set tuning. Though only two transistors are used, little gain is expected from an RF stage at these frequencies, so that sensitivity is quite good without this stage. An important advantage arises from the fact that the receiver can be tuned to a frequency where breakthrough of unwanted transmissions is…

Full circle Dear Don, I took the opportunity to find the March 2021 edition of PW where I wrote in about Pop Blundell and my connection both geographical and professional to the hobby that continues to give to myself as it does to many others. I opened the edition and was pleasantly surprised. You see since writing in I have (slowly) matured from an HF listener, modding my now loft-bound Realistic DX 394 receiver, to an intermediate licence holder with some home constructed kit and used Yaesu radios. Since that edition I have visited Bletchley Park (BP) and as a former Sigint operator it was a joy. The lovely tour guide was complimentary about my knowledge. The warm and welcoming (now) fellow hams at NRC BP were so encouraging that…