Innehållsförteckning för August 2022 från Practical Wireless

practicalwireless@warnersgroup.co.uk There are a number of Hamventions (amateur radio conventions) each year around the world, but the biggest one in Europe takes place on the last weekend of June in Friedrichshafen, Germany. The town lies on the banks of Lake Constance and the show is held in a modern exhibition centre three miles from the centre, next to the airport. The show runs for three days, Friday to Sunday, and attracts thousands of visitors. This year’s event was the first in three years due to the previous two events being cancelled for Covid reasons. We all wondered whether the enthusiasm to meet up again would overcome travel nervousness and recent travel disruptions – here’s what happened. Getting There and Staying There Although there is an airport at Friedrichshafen (FHN) there…

practicalwireless@warnersgroup.co.uk The source of a radio signal can be tracked down by using a direction finding (DF) set (a receiver with a directional antenna). So, using this ability we can have some fun. See if you can find the hidden transmitter station(s) before other competitors do. We make the assumption that radio waves propagate in a straight line from transmitter to receiver (which is not always true). However, this is a reasonable assumption if using low frequencies. An example of a directional antenna is a ferrite rod (as typically used in MW/LW radios). The ferrite rod antenna is simply rotated horizontally to find where the peaks and troughs are in signal strength. Turning through a full circle will reveal two peaks and two troughs. It will be noticed that the…

Longworthtim@gmail.com Although it’s not uncommon for us to mention schools contacts, the APRS digipeater on the International Space Station or the crossband repeater, astronaut activity from the ISS has been sparse in recent years in terms of making QSOs with ‘normal’ stations. In the last few days, reports have been coming in, mostly from North America of a number of contacts being made. Patrick Stoddard WD9EWK takes up the story. “In the past few days, hams across North and Central America have had the pleasure of hearing ISS crewmember Kjell Lindgren KO5MOS (yes, that is his personal callsign) working stations as NA1SS on the ISS cross-band repeater. ISS crews can pick up the microphone on the Kenwood TMD710G in the ESA Columbus module and join in the activity on the repeater, without…

ericgw8ljj@outlook.com Projects using valves are normally associated with high voltage power supplies varying between about one hundred and several hundred volts, and currents from milliamps to amps, depending on the circuits and purposes used. Some valve linear amplifiers have more that 1000V (1kV) as their power supply. Several decades ago valves and their associated power supplies were commonplace in the radio amateur’s shack as there was little other choice. In these modern times we are spoilt with semiconductors that operate from low voltages such as 12V and 24V as examples. There are amateurs today that still use valve transmitters of which some are homemade (home-brewed) and others that are vintage commercial and military, but today, health and safety is a big concern. This project is of interest for those that…

practicalwireless@warnersgroup.co.uk In this instalment of On a Budget we will examine some essential and desirable shack accessories, which will enhance your shack and operating. For many of these accessories you will find options on the second-hand market as well as new, allowing some keen purchases to be made. I am not listing these accessories in any particular order but will leave the reader to determine what is essential and what is desirable for their own circumstances, so let’s make a start. Power Supplies Power Supply Units (PSUs) are found in nearly every shack to provide (typically) 13.8V DC to power most transceivers that do not have an internal mains supply, and key accessories such as linear amplifiers, etc. Until a few years ago, power supplies were only available in ‘linear’…

THE FACE BEHIND THE CALL: Meet Mike Isherwood G4VSS, an amateur who plays with almost every aspect of the hobby and shares his passion with the whole family. VALVE & VINTAGE: Michael Jones GW7BBY gets to grips with the PCR receiver, reputedly based on the receive section of the classic Wireless Set No. 19. THE 2022 PW 70MHz CONTEST: Colin Redwood G6MXL has the rules and advice on taking part. SOLDERING JIG: Godfrey Manning G4GLM simplifies the fiddly problem of soldering wires together. PW AT 90: We round up the nine decades of PW’s success. There are all your other regular columns too, including HF Highlights, World of VHF, an Introduction to Microwaves and Data Modes as well as your Letters, the latest News and more. SEPTEMBER 2022 ISSUE ON…

Regrettably, to offset the increases in costs of energy, raw materials and postage charges the cover price of Practical Wireless has increased to £5.49; but you don’t have to pay that! We’ve frozen our subscription prices meaning you can save even more than before when subscribing to Practical Wireless! Take out a digital subscription today https://pktmags.com/pw-sub22 PREFER PAPER? Have the magazine posted direct to your door each month. To find our latest subscription offers please visit bit.ly/pw-sub22 or call 01778 395161 Telephone lines are open Monday to Friday 8am – 6pm and Saturdays 9am – 5pm…

practicalwireless@warnersgroup.co.uk The following is just a record of my build-out of an amateur radio station in a new house. It isn’t meant to be read as a ‘you must do this’ article, instead it describes my thinking and how I went about the installation. Readers will no doubt question some of my ideas and have better ideas and that is fine. Due to weather, financing and other, more important things in life, the project has proceeded in small, manageable stages over winter, spring and summer. A New Opportunity Since my ‘born again’ re-start with amateur radio about seven years ago, I’d been hankering after a bigger garden, more antenna space and a reduced probability of annoying my neighbours with ungainly and ‘ugly’ antennas. Due to the sort of constraints we…

teleniuslowe@gmail.com Welcome to the August HF Highlights. Solar activity continued to climb in May, with the sunspot number (SN) peaking at 173 on 17 May and the solar flux (SFI) peaking at 180 two days later. However, activity then declined and the SFI dropped below the 100 mark in early June. On the day this column was being finalised, 11 June, the SFI was 111 and the SN only 33, as can be seen in Table 1, which compares these figures with those recorded six months and 12 months ago. Queen’s Platinum Jubilee I write this as Her Majesty’s Platinum Jubilee celebrations are in full swing. Please send any reports and photos of your, or your club’s, activities with the GB70 or GQ prefixes, or the /70 suffix, to this…

military1944@aol.com Carrying on from my first part about repairing old valved radios, looking at getting some tools together, some test equipment items and finding a nice warm, brightly lit place to work and Part 2 describing valves and power supplies, we can now look at an actual radio set. With this in mind I spotted in a charity shop a nice old valved radio, which followed me home. Safety To reiterate, safety at all times. Check your supplies, your tools, the fuses fitted to any plugs and try to find a work location where it’s restricted access by others, children, pets and the like. You obviously do not want your wife, sorry, partner or children hurt but also, you do not want the dog to jump up and pull live…

CONSTRUCTION HUB/CLUB IN SE: A regional hub for makers and home brewers of radio related projects is proposed by Eric Stammers MOREQ and Graham Smith G4NMD. The idea is for a club that co-operates with knowledge, experience and test gear to support those who are already building or wishing to build radio related projects. It is hoped that the group can mutually support each other with: • Practical help with projects • Access to experience and advice • Access to tools and kit (some has already been donated by industry) • Inspiration for a new project • Time and space to work on a project in company with other like-minded people. It is initially suggested that the group will have a monthly evening meeting with perhaps a quarterly all-day meeting.…

gw0ugq@yahoo.com I was contemplating this idea quite a while ago. But sadly it had to be slightly shelved because of poor health and the outbreak of the dreaded COVID-19. A brief history of my QTH (see also qrz.com). As mentioned in a previous article (PW, April 2020), I now live in a high-rise multi-storey apartment block. The local CC will not allow any forms of HF antennas; hence the reason for experimenting with magnetic loops. My apartment block was built in the late 1960s and consists of reinforced concrete walls etc. So, it’s a little like living in a Faraday cage. But I cannot complain. I built this antenna with the possibility of trying a bit of portable work, but as mentioned above, I had to shelve the idea. The…

practicalwireless@warnersgroup.co.uk Many amateurs like a visual presentation of the contacts they have made, either for their own benefit or to illustrate to others the DX they’ve worked. There are a number of ways of mapping such contacts. I was recently made aware of one that I had not come across before, ‘ADIF Processor’ written by Mark Wickens M0NOM. ADIF Processor takes data from your .adi file, and enriches it with data from QRZ.COM where location data is missing, before producing a .KML file, which can be imported into Google Maps, Fig. 1. ADIF Processor The main advantage of using ADIF Processor over some of the other mapping systems, which rely on reports of signals received by distant stations and can’t handle telephony contacts, is that ADIF Processor can handle QSOs…

g0tmt@theshack.org.uk In the previous part we completed the transmit mixer, pre-driver, driver, PA and Low Pass Filter. In this final part of the series we’re going to construct the antenna changeover circuit and set it up for our semi-QSK operation. This circuit was originally published in PW back in May 2007 in an article by Rev George Dobbs G3RJV as part of his excellent series Carrying on The Practical Way. So, let’s take a look at the circuit, which appeared last month as the top half of Fig. 1, and see how it works. When the Morse key is pressed down it takes the cathode of D2 to ground. This makes TR1 and TR2 conduct allowing our 12V supply to pass through them. In essence they are acting like switches.…

roger@g3ldi.co.uk Mike G4GUG recently sent me some information on this device, Fig. 1. Essentially it is a self-contained transceiver with a built-in CW decoder and encoder, complete with its own keyboard. No computer is needed and it comes in a small box to enable portable operation. It was designed by Eric Anderson AF7YQ. It is a single band device, covering 40m and runs about 4W output, so not too much power, but QRP portable operation is the challenge and there are plenty of people doing that with a wide variety of rigs, not all having an in-built CW receive/transmit capability! This has been recently featured in the RadCom April edition should you wish to find out more. Mike was dubious about sending the information to me, knowing my purist views!…