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.

Sporadic E Propagation: The Science Behind Long-Distance FM Radio Reception

📡 Why did you just hear a radio station from 1,000 km away?

It sounds like magic — but it's pure atmospheric science. Sporadic E Propagation (Es) happens when dense ionized clouds form in the E layer of the ionosphere, bending FM signals back to Earth far beyond their normal range.

This in-depth article from vu3dxr.in covers everything: ✅ The science behind Es clouds ✅ Peak seasons (hint: June solstice is prime time!) ✅ Skip zones and multi-hop paths ✅ Best receivers, SDRs & antennas for FM DX ✅ Pro tips for catching openings in real time

Whether you're a seasoned ham or just curious about that mysterious distant station — this is a must-read!

🔗 https://vu3dxr.in/sporadic-e-propagation-the-science-behind-long-distance-fm-radio-reception/

#HamRadio #RadioDX #SporadicE #FMRadio #RadioPropagation #SDR #AmateurRadio

Radio Waves Weekly — Issue #004

Radio Waves Weekly — Issue #004: This Radio Waves Weekly brings exciting developments in Reverse Beacon Network technology, antenna innovations, and major updates from the world of SDR

Build Your Own Micro Power AM Transmitter!

Build Your Own Micro Power AM Transmitter!: Learn how to build a simple Micro Power AM Transmitter for short-range audio broadcasting. Great for beginners exploring amplitude modulation and radio circuits

Mini-Radio Firmware V3 Adds RTTY/CW Decoding and EiBi Integration

Mini-Radio Firmware V3 Adds RTTY/CW Decoding and EiBi Integration: Mini-Radio Firmware V3 by H. J. Berndt introduces built-in RTTY and CW decoding along with EiBi schedule integration, enhancing SI4735-based portable receivers.

Noise Cancelling Condenser Microphone

Kill the noise, keep the voice. 🤫🎙️

The VU3DXR Noise-Canceling Condenser Mic is a game-changer for clear communication. Perfect for #HamRadio, streaming, and voice-overs. High sensitivity meets professional noise rejection.

Get yours here: https://vu3dxr.in/noise-canceling-condenser-microphone/

#VU3DXR #RadioGear #AudioTech #Microphone

Build a High-Sensitivity Regenerative Receiver with 2N7000 MOSFET

Just came across a very nice DIY project on building a high sensitivity regenerative receiver using a 2N7000 MOSFET. The design shows how a simple regenerative circuit, using positive feedback and a single active device, can achieve impressive sensitivity on medium wave and shortwave bands.

The article explains coil winding, tuning, regeneration control and practical construction tips, making it ideal for radio amateurs, students and experimenters who want to understand classic receiver principles with modern, easily available parts. It is a great weekend build for anyone interested in analog RF, homebrew receivers and learning how regeneration can rival much more complex superheterodyne designs in sensitivity when carefully adjusted.

The full project is available at https://vu3dxr.in/build-a-high-sensitivity-regenerative-receiver-with-2n7000-mosfet/

VK3YE’s AGC circuit for ubitx

If you’re into homebrew radio or ham gear mods, here’s a neat find: a clever non-invasive AGC (Automatic Gain Control) circuit designed by VK3YE for the popular µBITX transceiver. Instead of modifying internal gain stages, this design uses a conventional audio AGC to drive an LED-LDR pair that automatically controls the audio level at the volume pot — helping tame strong signals, reduce distortion, and make listening more comfortable. It’s a simple but elegant way to add AGC where the stock uBITX doesn’t have one built in.

VK3YE’s AGC circuit for ubitx

VK3YE’s AGC circuit for ubitx uses a conventional audio AGC circuit which drives a LED that is optically coupled to a Light Dependent Resistor (LDR).

OpenSourceSDRLab PortaRF: The Next Evolution in Portable Software-Defined Radio

OpenSourceSDRLab PortaRF: The Next Evolution in Portable Software-Defined Radio: The OpenSourceSDRLab PortaRF is ultimate portable SDR, integrating the HackRF and PortaPack into one device. Explore its architecture and key features

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.

Simple Receiver S-Meter Circuit for Your Radio

Simple Receiver S-Meter Circuit for Your Radio: build a receiver S-meter circuit using op-amp 741 and MPF102 FET. Perfect project for measuring signal strength in radio receivers.

Simple Speech Processor for Homebrew SSB Transceivers

Simple Speech Processor for Homebrew SSB Transceivers: A simple speech processor circuit for homebrew and QRP SSB transceivers, improving average talk power while maintaining clear and natural audio quality.

Good speech processing can make a dramatic difference to how a low-power SSB signal sounds on air. In homebrew and QRP SSB transceivers, transmitter audio is often clean but lacks average power, making signals sound weak during normal conversation. The compact Simple Speech Processor circuit shown here addresses that exact problem by increasing average talk power while preserving intelligibility and keeping distortion under control.

Housing the LARCSet: A Community-Designed 3D-Printed Enclosure

Housing the LARCSet: A Community-Designed 3D-Printed Enclosure: A detailed look at a 3D-printed enclosure for the LARCSet transceiver, featuring Peter Marks’ open-source design and real-world build photos by Michael VE3WMB.