TL071 Audio Compressor Circuit

The TL071 operational amplifier makes an excellent foundation for DIY audio compressor circuits. This single-supply design TL071 Audio Compressor offers reliable dynamic range control for musical instruments and recording applications.

TL071 Audio Compressor Circuit

Simple 2M VHF Sleeve Dipole Antenna for Rapid Field Deployment

When communication matters most, having an antenna you can build quickly from available materials becomes essential. The 2-meter Sleeve dipole antenna is one of the simplest and most reliable emergency VHF antennas you can assemble directly from the end of a transmission cable. With only a short whip, a piece of copper braid and an aluminium tube for stiffness, you can create a surprisingly efficient vertical radiator for 2 meters.

Simple 2M VHF Sleeve Dipole Antenna for Rapid Field Deployment

Extended Lazy-H Antenna: A Classic Multiband Wire Design from QST

Extended Lazy-H Antenna: A Classic Multiband Wire Design from QST: The Extended Lazy-H antenna, introduced in QST in 1955, is a balanced, open-wire-fed HF antenna offering efficient multiband operation.

Microphone Pre-Compressor Circuit for SSB Transceivers

Microphone Pre-Compressor Circuit for SSB Transceivers: A practical microphone pre-compressor circuit for SSB transceivers using JFET and transistor stages. Improve transmit audio clarity and power in amateur radio

DIY 145 MHz Twin Delta Loop Antenna for Ham Radio Operators

DIY 145 MHz Twin Delta Loop Antenna for Ham Radio Operators: A complete guide to building 145 MHz Twin Delta Loop antenna with dimensions, construction tips, feeding method, and performance advantages for VHF ham radio.

UR0GT Broadband Avia Antenna (RW4HVN Mod): The Ultimate Wideband VHF Antenna Guide

UR0GT Broadband Avia Antenna (RW4HVN Mod): The Ultimate Wideband VHF Antenna Guide: Detailed guide to building UR0GT Broadband Avia Antenna modified by RW4HVN. Covers dimensions, design principles, SWR performance, construction details

Compact 40M HF Antennas: Short Dipoles & Short Verticals

Compact 40M HF Antennas: Short Dipoles & Short Verticals: Explore short dipole and vertical antennas for 40 m HF operation—ideal for limited spaces, field setups, and portable ham radio stations. 40M HF Antennas

40m Vertical Antenna: Compact Base-Loaded Design for Powerful HF Operation

40m Vertical Antenna: Compact Base-Loaded Design for Powerful HF Operation: Build an efficient 40m vertical antenna with a 15µH base loading coil and short radiator. Ideal for compact HF setups and portable amateur stations

RW4HFN Balcony Antenna for the 20-Meter Band

RW4HFN Balcony Antenna for the 20-Meter Band: Discover the RW4HFN balcony antenna design for the 20-meter amateur radio band—ideal for limited spaces. Includes schematic, dimensions, and inductance values

Shortened G5RV Antenna – DX Power in a Smaller Package

Shortened G5RV Antenna – DX Power in a Smaller Package: A compact, multi-band wire antenna based on the legendary G5RV design —specifically, a shortened version of G5RV antenna optimized for the 14-50 MHz range.

Mosquito TRX: Single-MOSFET 40-Meter (7030 kHz) CW Transceiver

Mosquito TRX: Single-MOSFET 40-Meter (7030 kHz) CW Transceiver: Detailed explanation of Mosquito TRX circuit. Learn how the IRF510acts as crystal oscillator/PA for QRP transmission and direct conversion mixer for 7030 kHz

Building Sovina 40M Class E CW Transmitter with BS170 MOSFETs

Building Sovina 40M Class E CW Transmitter with BS170 MOSFETs: High-efficiency 40M CW Class-E CW transmitter using BS170 MOSFETs and 74HC02. Complete circuit explanation and build notes for QRP hams.

W3DZZ Multi-Band Antenna 80m-10m Trapped Dipole

W3DZZ Multi-Band Antenna 80m-10m Trapped Dipole: Learn how to construct W3DZZ Multi-Band Antenna. Detailed instructions on 7MHz coaxial traps, wire dimensions, and LC tuning for 80, 40, 20, 15, and 10 meters.

Build a Miniature FM Transmitter – DIY Electronics Project

Build a Miniature FM Transmitter – DIY Electronics Project: Miniature FM Transmitter is a compact and effective project ideal for experimenting with radio communication. Whether you’re a student or an amateur radio enthusiast, this circuit offers a great introduction to the basics of FM transmission and audio electronics.

Microphone compressor using two transistors

Microphone compressor using two transistors: This microphone compressor circuit utilizes a two-stage amplification design for dynamic range control. Initially, the input signal enters through MK1, a microphone input connector. Subsequently, the signal passes through C1 and C3 coupling capacitors for DC blocking.

Radio Waves Weekly — Issue #007

Radio Waves Weekly — Issue #007: This week: 3Y0K is finally on the air from Bouvet Island — the most remote uninhabited island on Earth — and the pile-ups are epic. The Rebel DX Group is next up with a Kanton Island activation starting March 25. Plus a pocket-sized Indian SDR that does FT8 without a computer, the freshest QRP Labs kit, two wire antennas you can build this weekend, and a handful of contests and events to fill your log before spring.

FT2 Digital Mode: Latest News, Software Updates, and Ham Radio Adoption

FT2 Digital Mode: Latest News, Software Updates, and Ham Radio Adoption: FT2 is the fastest FT-family digital mode ever built — completing QSO in seconds. Discover its origins, Decodium vs WSJT-X Improved schism, adoption trends,

Low-Loss Feedline on a Budget: Building 450 to 600 Ohm DIY Ladder Line from Common Materials

Low-Loss Feedline on a Budget: Building 450 to 600 Ohm DIY Ladder Line from Common Materials: A complete technical guide to DIY ladder line for amateur radio. Build 450–600 ohm open-wire feedline cheaply, with less loss than coax on any HF band.

Shortened Inverted V Antenna for 80 Meters (3.700 MHz)

Shortened Inverted V Antenna for 80 Meters (3.700 MHz): Operating on the 80-meter band can be challenging for radio amateurs with limited horizontal space. A full-length 80-meter dipole requires nearly 40 meters of wire, which is often impossible to install in urban or restricted locations. To solve this, PY7DM Arimatea designed an efficient Shortened Inverted V Antenna for 3.700 MHz, using loading coils and precise wire lengths to compress the antenna into a compact, manageable size without sacrificing performance on the lower HF bands.

Radio Waves Weekly — Issue #006

Radio Waves Weekly — Issue #006: Welcome to Issue #006 of Radio Waves Weekly! This week: an Arduino that transmits clean SSB with 8 components, an open-hardware SDR transceiver with PureSignal TX, a garden fence turned into a stealth HF antenna, and a broadband V wire that covers every HF band without a tuner.