DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
“DIY” on DXR Electronics Bits is where practical ham radio projects come to life. Here you’ll find buildable circuits, antennas, receivers, preamps, audio tools, and experimental rigs designed for real‑world shack and field use. From compact HF antennas for small spaces to regenerative receivers, QRP transmitters, and uBITX add‑ons, each article focuses on parts you can actually source and solder on the bench.
This simple two-stage AM transmitter uses an oscillator and a transistor RF amplifier to deliver about 1 W output on HF bands. It supports common transistors like BD139 or 2N3553, uses a modulation transformer for audio input, and serves as a beginner-friendly QRP project with stable performance
Build a Simple Series Modulated AM QRP HF Transmitter for the 40m or 80m bands. This DIY guide includes a stable crystal oscillator schematic, series modulation tips, and power amplifier details for low-power (QRP) ham radio operation.
Looking for a fun weekend project? Discover the OXO QRP transmitter—an elegantly simple, high-performance HF rig perfect for homebrew enthusiasts and minimalist radio operators
Simple audio compressor for SSB HF Radio rigs An audio/speech compressor is a device that reduces the dynamic range of the audio signal. This means that it makes the loud parts of the signal quieter and the quiet parts of the signal louder. This can be useful for SSB HF radio rigs because it can […]
NE555 based Microphone amplifier IC NE555 or commonly known as 555 is an IC that is well known among electronics practitioners as an IC for timers, and can be used to form monostable or bistable multivibrator circuits. But not many know that the 555 IC can also be used as an audio signal amplifier. By […]
Stop fading into the noise! Build this simple, low-cost speech compressor using the LM324 quad op-amp to ensure your voice stays loud and clear on the airwaves.
Amateur Radio – End fed Halfwave antenna – Web resources and links An end-fed half-wave (EFHW) antenna is a type of radio antenna that is a half-wavelength long and has its feed point at one end. This makes it a very simple and compact antenna, and it is often used for portable or temporary applications. […]
Audio processors and Speech compressors are important in SSB radio because they can help improve the transmitted signal’s quality. Here are complete resources and links available in the internet connected to Mike Preamplifier/Speech compressors/Speech Processors Dyna Audio compressor Noise Canceling Electret Microphones – WB9YBM Microphone Speech Processor Microphone Amplifier with ALC Audio compression with transistors […]
This article presents a simple, low-cost audio compressor circuit designed to stabilize microphone signal levels. It reduces dynamic range by softening loud sounds and boosting weak ones, improving clarity and intelligibility. Built with basic components, it suits amateur radio and DIY audio setups, offering consistent output without complex or expensive hardware.
A short linear loaded ham radio band HF antenna is a type of antenna that uses linear loading to reduce its physical length. Linear loading is a technique that involves adding parallel conductors to the antenna elements. This increases the antenna’s effective length, allowing it to operate at a shorter physical length. Short linear loaded […]