DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
Audio compressor circuits and DIY audio projects including VCA, op-amp compressors, and signal dynamics control for ham radio and audio electronics.
Clean, punchy audio is critical for effective SSB communication, especially when operating QRP or low-power HF transceivers. A microphone pre-compressor placed ahead of the transmitter’s audio input can significantly improve average modulation levels without introducing harsh distortion. The attached Microphone Pre-Compressor circuit is a practical, discrete-component design well suited for homebrew and experimental SSB rigs.
Simple speech processor for homebrew and QRP SSB transceivers that boosts average talk power while preserving natural audio. BF245 mic preamp, dynamic compression stage, and TL071 output amplifier improve readability and on-air presence.
Simple microphone preamplifier with diode clipper to boost and limit SSB audio for amateur radio transceivers. Prevents over-modulation, improves speech clarity, and delivers clean transmit audio in DIY HF radio setup
A speech processor is an essential component in amateur radio and audio systems that enhances voice clarity and intelligibility. This comprehensive guide will walk you through building a simple yet effective simple speech processor circuit using the LM358 operational amplifier and discrete components. A speech processor is an electronic device that modifies audio signals to […]
Discover how to build a Logarithmic Audio Compressor circuit for smooth, natural-sounding audio. This guide features a high-performance schematic using precision op-amps and log-antilog transistors to prevent distortion while maintaining consistent signal levels for amateur radio and pro-audio projects.
Learn how to build a simple and effective Audio Clipper Circuit using BC547 transistors and 1N914 diodes. This DIY guide covers schematic details, component selection, and how to prevent overmodulation in amateur radio transmitters for clearer, peak-limited audio.
The circuit shared here is a Microphone Preamplifier with Audio Peak Limiter, often used in audio recording, amateur radio, or intercom systems. It amplifies weak microphone signals and includes peak clipping diodes to prevent signal distortion from loud inputs. Looking to boost your microphone signal while keeping audio distortion in check? This two-stage transistor microphone […]
The main goal of TL081 Speech Processor circuit is to boost, shape and process your voice signal before sending it to the radio transmitter
The NJM4558 audio compressor represents one of the most reliable and widely-used integrated circuits in professional audio applications. Furthermore, this dual operational amplifier IC has become the cornerstone of countless audio compression circuits due to its exceptional performance characteristics and versatility. The NJM4558 audio compressor circuit shown in the schematic demonstrates a sophisticated approach to […]
This TL071 audio compressor circuit uses a single-supply design with a TL071 op-amp as a voltage-controlled amplifier to manage audio levels. It includes input coupling, peak detection, and RC timing networks to control compression, delivering stable, low-noise dynamic range control for audio and radio applications.