M7ENP Adventures & Experiments

Introduction Oscillators are fundamental components in the world of electronics, and their applications are vast, ranging from generating radio signals to powering precision clocks. In this blog post, we'll explore the inner workings of oscillators and demystify the process behind their ability to produce continuous, periodic waveforms. The Core Concept: Feedback Loop At the heart of an oscillator lies a concept known as a feedback loop. This loop is the key to understanding how oscillators work. Let's break it down step by step: 1. Amplification An oscillator begins with an initial disturbance or noise. This can be random electrical fluctuations, external signals, or even intentional triggers. The first step is to amplify this initial signal. An amplifier within the oscillator circuit boosts the signal to a level where it can sustain oscillation. 2. Feedback Network The amplified signal is then fed back into the circuit through a feedback network. This network includes compone

The J-pole antenna is a type of end-fed antenna that is popular among ham radio operators for 2m and 70 cm operations. It consists of two parallel conductors, with the top section being a half-wave element and the bottom section being a quarter-wave matching stub. The name "J-pole" comes from the shape of the antenna, which looks like the letter "J" when it is bent at the bottom. One of the key features of the J-pole antenna is its omnidirectional radiation pattern. This means that the antenna can transmit and receive signals equally well in all directions, making it a great choice for general communication purposes. Another advantage of the J-pole antenna is that it does not require any radials or ground plane, which reduces the wind resistance and simplifies the installation process. To construct a J-pole antenna, we first need to determine the length of the half-wave element. This can be calculated using the formula: Length = 468 / frequency in MHz For example, i

Hi everyone, I'm excited to share with you a new textbook that I just finished reading: PySDR: A Guide to SDR and DSP using Python. This book is an absolute must-read for anyone interested in learning about software-defined radio (SDR) and digital signal processing (DSP). PySDR is written by Dr. Marc Lichtman, a well-known expert in the field of SDR. He brings his extensive knowledge and experience to the book, and it shows. The book is packed with information, but it's written in a clear and engaging style that makes it easy to read and understand. One of the things that I really liked about PySDR is that it covers a wide range of topics. From the basics of SDR and DSP to more advanced concepts such as modulation and demodulation, filtering, and spectrum analysis, PySDR has it all. I learned a lot from this book, and I'm sure you will too. Another thing that I really liked about PySDR is that it's very hands-on. The book includes numerous exercises that allow you to ap

The world of ham radio is filled with fascinating people, ideas, and projects. One such project that caught my attention is the "continuously loaded, helically wound vertical antenna" designed by Bev AH6NF (YL). In this article, we will analyze the design, materials, and steps to build this antenna, and then we'll give it a try ourselves to see how it performs. Design The design of this antenna is simple yet effective. It is a vertical antenna that is helically wound with a 91cm stinger. The stinger can be folded along the 122cm mast for easy storage. The antenna is continuously loaded, which means that it is designed to operate on multiple bands without the need for an antenna tuner. Materials The materials needed to build this antenna are readily available and affordable. The list includes: 1.22 meters of 1.27 cm white PVC water pipe 9.14 meters of 1.63 mm² insulated electrical house wiring 2.38 mm diameter brass brazing rod, 91 cm long Miscellaneous junkbox stuff Numbe

Building a Dual Band 2m/70cm Yagi Antenna: Tips, Formulas, and Pros and Cons If you’re looking for a reliable and high-performing antenna for your 2m/70cm radio, a Yagi antenna might be just what you need. Yagi antennas are known for their directional properties, which can help you focus your transmission in a particular direction, resulting in better signal strength and clarity. In this post, we’ll take a closer look at how you can build a dual-band 2m/70cm Yagi antenna, including the construction tips, formulas, and potential pros and cons of using this type of antenna. Before we get started, it’s important to note that building a Yagi antenna requires some basic knowledge of antenna theory and construction, as well as some specialized tools and materials. If you’re new to antenna building, we recommend that you consult with an experienced ham radio operator or antenna builder before attempting to build your own. What is a Yagi Antenna? A Yagi antenna is a type of directional antenna

Introduction Cubical quad antennas have been a popular choice among amateur radio operators for many years, due to their relatively simple construction and high gain. This type of antenna is especially popular for use on the 2-meter band, as it can provide excellent performance with only a moderate-sized structure. In this blog post, we will discuss the construction of a 2-meter cubical quad antenna, including construction tips, formulas, and the potential pros and cons of using this type of antenna. What is a Cubical Quad Antenna? A cubical quad antenna is a type of directional antenna that consists of a square or rectangular loop of wire, supported by a framework of poles or wires. The loop is fed by a single coaxial cable at one corner, and the other three corners are connected to a set of elements called "directors" or "reflectors," depending on their location and function. The directors and reflectors are typically shorter or longer than the main loop, and thei

As a ham radio enthusiast, you know that having the right equipment is key to achieving optimal performance from your setup. At TechDarren , we share your passion for ham radio and are dedicated to providing you with the highest-quality equipment available. One of the key things we've learned in antenna construction is the importance of using the right materials. That's why we're excited to offer you a selection of antenna traps made from high-quality materials that are designed to withstand the toughest weather conditions. In addition to our antenna traps , we also offer a range of other Antenna equipment made from the best materials available. For example, we use a 40mm form of Polypropylene tube for its durability and weather resistance. When it comes to connections, we find that mill spec RG58 low loss cable that is crimped and soldered is the way to go. To protect against the elements, we always use UV-resistant heat shrink tubing, and for all fixings, we use A2 stain

In recent years, digital voice communication has become more accessible than ever before. Digital communication is popular because it offers better sound quality, longer range, and more reliable connections. The MMDVM hotspot is one of the devices that have revolutionized digital voice communication. In this blog post, we will take a closer look at what the MMDVM hotspot is, its benefits, how it works, and how to set it up. What is an MMDVM hotspot? The MMDVM hotspot is a small, low-cost device that allows users to connect to digital voice networks using a handheld radio or mobile device. It acts as a hotspot, similar to how Wi-Fi hotspots work, and allows users to connect to digital voice networks from anywhere with an internet connection. The MMDVM hotspot can be used with popular digital voice communication protocols like DMR, D-Star, and Fusion. Benefits of Using an MMDVM Hotspot The MMDVM hotspot offers several benefits for users, including: Increased Range: The MMDVM hotspot can

The documentary "Ham Radio: The First Social Network" explores the history and appeal of this hobby, and sheds light on how it has evolved over the years. The documentary takes us on a journey through the history of ham radio, starting from the early days of wireless communication to the present day. We learn about the pioneers who made important contributions to the development of this hobby, such as Guglielmo Marconi, who is credited with inventing the first radio telegraph system in 1896. The documentary also explores the cultural and social impact of ham radio. It highlights how ham radio enthusiasts have used this technology to communicate with people from all over the world, forming a global community of like-minded individuals who share a common interest in communication and technology. The documentary also shows how ham radio has played a role in various important events throughout history, such as the Cuban Missile Crisis and the September 11th attacks. One of the mo

Greetings! I'm excited to share with you some information about my SatNOGS ground station located in the UK . I built it from scratch, using a self-built UHF/VHF turnstile antenna and a Raspberry Pi for data processing. In this blog post, I'll provide you with a comprehensive overview of my SatNOGS ground station, including the satellite signals it receives, and how it receives and decodes those signals. First, let's talk about the satellites that my station has received. The satellites that I've managed to receive data from include NOAA-19, FOX-1A, and the International Space Station (ISS). NOAA-19 is a critical weather and environmental monitoring satellite that provides valuable data for forecasting. It orbits the Earth in a polar orbit, passing over the poles at an altitude of approximately 870 km. The data that I've received from NOAA-19 has been useful in helping me to better understand the environment and climate around me. FOX-1A, on the other hand, is a sma

The Key to Stronger Signals Ham radio enthusiasts understand the importance of having a strong antenna system in order to effectively communicate with other operators. But with so many different types of antennas on the market, it can be difficult to know which one is the best fit for your needs. In this blog post, we'll break down the different types of antenna systems available for ham radio use and help you determine which one is right for you. First, let's start with the basics. An antenna is essentially a device that converts electrical energy into radio waves, and vice versa. When you transmit a signal, the energy is sent through the antenna, which then converts it into radio waves that can travel through the air. When a signal is received, the radio waves are picked up by the antenna and converted back into electrical energy that can be understood by your radio. There are many different types of antennas available for ham radio use, including vertical, horizontal, and di

This is a project that looks very interesting, it's a dual vfo SSB transceiver published by Pete Juliano, radio ham N6QW and co-host of the popular podcast Solder smoke. so let's get started the first job is to read all the documentation and then read it again. After reading the documentation and printing the documents I emailed Pete and asked if I could get a copy of the Arduino sketch for this project, Pete sent me the sketch as requested. Fantastic thanks, Pete. OK, next job is to get all the parts together,  all parts are all available and as a bonus, we managed to get the mixers ADE-1 supplied by mini circuits in NewYork and mini circuits supplied them free of charge as a sample. sofar so good, ok so let's get a bill of materials together. To do this we used my favourite cad and PCB design tools, Using Easy EDA we started to sketch up the schematics and create a list of part, why redraw the schematics? we hear you ask, we did this so at a later date if everything works

 ARISS SSTV Event Set for April 11-13, 2022 From the International Space Station, an ARISS Slow Scan TV (SSTV) event is planned (ISS). The event is scheduled to begin on April 11 at 16:30 UTC for setup and operation and will finish on April 13 at 12:00 UTC. These are approximate timings that may fluctuate based on crew availability. Images will be downlinked at 145.8 MHz +/- 3 KHz for Doppler shift, and the planned SSTV mode of operation is PD 120. This event will commemorate Cosmonautics Day and Women in Space. Radio enthusiasts participating in the event can publish and see images in the ARISS SSTV Gallery at https://www.spaceflightsoftware.com/ARISS SSTV/. UPDATE 12/04/2022 Images captured today 12/04/2022 UPDATE 13/04/2022 Images captured today 13/04/2022

  RSØISS - SSTV activity Thursday April 7 start about 08:00 GMT, stop about 15:35 GMT* Friday April 8 start about 08:40 GMT, stop about 16:10 GMT* Description: Russian cosmonauts on the International Space Station (ISS) are planning to transmit Slow Scan TV images on 145.800 MHz FM using the SSTV mode PD-120. The transmissions are part of the Moscow Aviation Institute SSTV experiment (MAI-75) and will be made from the amateur radio station RS0ISS in the Russian ISS Service module (Zvezda) using a Kenwood TM-D710 transceiver.  Thursday April 7 start about 08:00 GMT, stop about 15:35 GMT* Friday April 8 start about 08:40 GMT, stop about 16:10 GMT* *Dates and times subject to change. For more information on ARISS SSTV, please visit: https://www.spaceflightsoftware.com/ARISS_SSTV/ Update 11/04/2022 We managed to capture 3 images using are Satnog Ground Station 1404 InSight 1 Ground Station https://network.satnogs.org/observations/5749089/ https://network.satnogs.org/observations/5749090

Queen’s Platinum Jubilee Special Event Station As Her Majesty The Queen becomes the first British monarch to reach a Platinum Jubilee, the nation is celebrating this latest milestone in Her Majesty’s record-breaking reign. Ofcom has generously agreed to an RSGB request that radio amateurs licenced by Ofcom use the special RSL 'Q' to commemorate Her Majesty The Queen's Platinum Jubilee. This will be accessible for usage until June 2022, and a Notice of Variation will be required, which will be available at RSGB.org . The Society is also planning other events and activities that it thinks will appeal to a broad audience. More information will be revealed in the coming weeks.  We will be active with special call MQ7ENP from Cotswolds, Worcestershire, England, during June 2022, commemorating the Platinum Jubilee of Queen Elizabeth II. We will be operating on the HF Bands.