Practical WirelessJune 2024的目錄

Just as a quick recap, Part 1 of this series provided the basic project overview and some advice on construction methods, PCBs, etc. while Part 2 covered the construction details for the Variable Frequency Oscillator (VFO). This part covers the receiver side of the project. Combined with the VFO, the receiver board will enable you to listen to the band while you are building the rest of the project, which is always a very satisfying experience. Morse, FT8 and SSB signals can all be demodulated. You will find that the instructions in this series repeat component orientation warnings and testing procedures; this is deliberate. This month the main advice is in the sidebar – I recommend going through it as you complete each stage. The series has been written to…

The first use of radio and the telegraph/telephone by military forces inevitably led to the exploitation of these systems by their prospective enemies. Radio signals were (are) intercepted and telephone lines ‘tapped’ (or is that nowadays hacked?). When found, advantageous signals were ‘jammed’ although in many cases it is more fruitful to allow communications to continue and glean as much information from them as possible. Even a signal just being there can give away important information about an enemy’s activities. With the onset of WW2 Electronic Warfare started to come of age. During early August 1939 the German airship Graf Zeppelin carried out what is now often referred to as a ‘Ferret’ mission along the east coast of England to try and analyse signals that were coming from the series…

Welcome to the June HF Highlights. This is the first column I am compiling from England, having moved back to the old country from Bonaire in late March. As we are renovating our home I am unlikely to be active for a while yet, which makes it all the more important for me to receive your input to the column. This month we have contributions from no fewer than six countries including, in what must surely be a first, the Solomon Islands. But if you are at all active on the HF bands, no matter on what modes and whether running QRO or QRP, please do let us know about your activity or your plans for your station. Do you enjoy DXing, working special event stations, collecting certificates, or do…

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 certificates will probably be distributed by email. 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 place using single sideband (SSB). Most stations use horizontally polarised…

The SDRplay RSP1B UK firm SDRplay has a dedicated following among many radio enthusiasts, citizen scientists, students and DXers, especially those new to SDR. The firm is very active at radio shows on both sides of the Atlantic and is known to engage actively with customers, listeners and developers. For many hobbyists and professionals, the main advantage of the SDRplay ‘black-box’ SDR receivers and proprietary software programs that come with them (SDRuno & SDRconnect) is their adaptability, openness to development and third-party applications, plus their useability with a growing range of different computer platforms and architectures. At the time of writing, for example, for those interested in receiving Trunked Radio, the SDRtrunk program was working with the new RSP1B unit. https://tinyurl.com/mpkvam6h https://github.com/DSheirer/sdrtrunk/wiki The SDRplay range offers 1kHz to 2GHz coverage…

Raspberry Pi 5 - Real-Time Clock Before the launch of the Pi 5, we had to add a hardware real-time clock module if we wanted to use the Pi for time-critical applications, i.e. data modes when not connected to the internet. However, the latest Pi 5 includes real-time clock (RTC) hardware, which can be battery-backed using an external battery. The consistent time source makes the Pi 5 ideal for use off-grid, such as when operating in remote locations with no cellphone signal. The RTC hardware uses a standard 32.768kHz crystal reference for the clock functions and integrates with the Linux operating system. As a result, the RTC can be used to schedule events and keep track of time. The RTC reference crystal is a standard 50ppm unit, which, at its…

ALEX LOOP REVIEW: Richard Constantine G3UGF reviews the ‘Amazing Alex Loop Hampack’. VALVE & VINTAGE: Bernard Nock G4BXD introduces readers to a variant of the popular HRO receiver. PHaRLAP: Nils Schiffhauer DK8OK introduces PHaRLAP – an HF laboratory between heaven and earth. MY NEW MAGNETIC LOOP APPROACH: Maurice Webb GW0UGQ returns with a new HF loop design. ANTENNA SWITCHING SOLUTION: Samuel Ritchie EI9FZB starts a project for the remote switching of antennas There are all your other regular columns too, including HF Highlights, World of VHF, Antennas, Book Reviews, Vintage TV & Radio, the Face Behind the Call and Data Modes as well as your Letters, the latest News and more. The publishers reserve the right to change content according to circumstances. JULY 2024 ISSUE ON SALE 13 TH JUNE…

Quiet Radio introduce the new Aziloop dual-mode (LF/HF) antenna system QuietRadio have launched Aziloop, a groundbreaking electronically rotatable dual-mode antenna system for LF and HF reception. Aziloop’s unique Stepped-Azimuth™ technology creates an electronically rotatable receive antenna with 72 headings in K9AY mode or 36 bi-directional headings in loop mode. Primary frequency coverage is from 20kHz to 10MHz, with secondary coverage up to 30MHz. QuietRadio supply the LCU (Loop Control Unit), the CIU (Common Interface Unit) and the Windows control software. The antenna, comprising a pair of orthogonal wire loops plus a ground for K9AY mode, is sized by the user. A small footprint, low visual impact antenna usually suffices. Key features: • Electronically rotatable in 5° steps with a response time of just 60ms, the antenna itself remaining fixed.• A…

The Take 20 series has been about construction projects that consist of 20 components or less and cost less than £20 or 20 shillings in the old days. Nowadays, modules can be bought on eBay and other suppliers that can cost less than the cost of single components. With this in mind, I have written this Take 20 project that should cost less than £20, but uses only a handful of easy-to-obtain small modules. The project is an Arduino Nano based VFO or RF Signal Generator using only three modules. The VFO/Signal Generator gives an output from 10kHz – 225MHz. I have built several of these in the past and have found them easy to build and get going without having to get too involved in the programming. Circuit The…

In the February edition of this series I took a trip down memory lane and built a Matchbox MW receiver of the type first described in the late 70s and built by me in the early 80’s. It was a fun yet effective project. The building of that receiver got me thinking about the possibilities that a matchbox may hold as a project enclosure and I began to consider if I could build a transmitter in one. Not just a novelty but a transmitter that could bring real-world CW contacts cheaply and in a tiny package. Back when I was first licensed in the early 80s, I was a member of the G-QRP Club and an avid reader of their magazine, SPRAT. Indeed, I am still a member today. In…

While Logbook of The World (LoTW) is increasingly popular with amateurs seeking confirmation of QSOs for award purposes, many amateurs still like to send and receive paper QSL cards. This month I am looking at an alternative way of producing and sending QSL cards. There are several ways that QSL cards can be sent and received. One way is to send cards individually by post direct to the station that you’ve contacted, usually enclosing some sort of payment (typically US$2) for return postage or a stamped addressed envelope for contacts within your own country. A second way is to post a batch of QSL cards to a QSL bureau, such as the one operated by the RSGB. A third way, probably best suited to stations making many contacts, for example…