Arduino QRP Transceiver: DIY Success on HF Bands 

Technical Reference/Arduino
This article introduces an Arduino-based QRP CW Transceiver designed for lower HF bands. The journey begins with the Wotduino, evolving from a keyer to a multi-mode beacon. The development includes a QRP transmitter and culminates in a receiver inspired by Roy Lewallen design. The transceiver, controlled through a control bus features a signal path, modulation, filtering, and adjustable frequency settings. Despite initial testing intentions, successful QSOs on 80 and 40 meters showcase its functional capabilities.

RF-Quiet Solar PV for Ham Radio 

Technical Reference/Radio Frequency Interference
This article discusses the potential for solar power systems to coexist harmoniously with amateur radio, challenging the notion that they are inherently incompatible. Drawing from personal experience, the author emphasizes the importance of selecting RF-quiet components, focusing on series-string Sunny Boy grid-tie inverters. The article also highlights considerations for system design and limitations based on roof orientation, shading, and array size. Overall, it presents a valuable perspective on creating a radio-friendly solar PV setup.

IC705 GoBox: A Portable Windows-Based Solution for All-Digital Modes 

Technical Reference/Ham Radio Go Kits
This project details the creation of a portable GoBox housing an IC705, Windows 11 PC, and Bluetooth microphone. The robust setup, enclosed in a weatherproof Hofbauer Explorer Case, ensures stability and functionality for QRP and emergency radio activities. The aluminum-mounted devices minimize RF interference, and a built-in LifePO4 battery powers the 10.1 TFT touch LED monitor, providing approximately 12 hours of use in receive mode. With a focus on grab-and-go versatility, this GoBox stands as an efficient solution for outdoor ham radio operations.

Understanding Impacts of 75-ohm Devices in 50-ohm Systems 

Technical Reference/Coax Cables and Connectors
This article explores the implications of using 75-ohm devices, common in TV setups, within 50-ohm systems. While mismatched cables and connectors may lead to minimal consequences in receive-only setups, potential losses and reduced isolation in splitters and taps are examined. The article concludes that, for general applications, inexpensive TV-type components can offer reasonable performance with some trade-offs

Enhancing Frontend Performance with Optimized Band Pass Filters 

Technical Reference/Filters
This article explores the nuanced design challenges of Band Pass Filters (BPF) in radio receivers, balancing low insertion loss, high stop band rejection, and narrow bandwidth. The focus is on the "Series-Trap, Shunt-C" topology, resonator count impact, and meticulous layout design for superior stop band performance across various frequency bands

Enhancing Icom IC-7300 RX Antenna 

Radio Equipment/HF Transceivers/Icom IC-7300
Despite the model limitations, such as a single TXRX antenna connector, the author shares a reversible modification involving a coax relay for enhanced functionality, demonstrating the transceiver's adaptability and customization potential.

Yaesu FT-817 Audio Enhancement: Heathkit-inspired Homebrew Project 

Technical Reference/Audio
Inspired by Heathkit, author aimed to enhance his Yaesu FT-817 with audio and RF processing. Design goals included a compact enclosure, PCB simplicity, matching jacks, a visual meter, and a built-in signal generator. Despite challenges in finding a suitable compressor IC for a 5V DC mic jack, he chose the Analog Devices SSM2165/2166 series. Prototyping with a solderless breadboard, author planned a PCB layout for its versatile performance in communication use.