Build the Commando AM transmitter — a crystal-controlled three-transistor AM circuit with oscillator, buffer, and RF power stages delivering stable modulation for HF experimentation
HF
The HF category brings together all content related to high‑frequency bands, from 160 m through 10 m, with emphasis on practical antennas, propagation, and station hardware. Here you will find compact 40 m verticals, multiband wire antennas, HF QRP transmitters, SDR transceivers, and accessories designed for real‑world home and portable operation. Articles often include measured SWR curves, on‑air reports, and build photos so you can understand how a design will behave before you start cutting wire.
There is a strong focus on getting HF on the air from small Indian plots, apartments, and field locations without sacrificing too much performance. Whether you are preparing for your first HF QSO, improving your 40 m NVIS coverage, or chasing DX on higher bands during good conditions, this section provides tested ideas to upgrade your HF station step by step
TL081 Speech Processor for HF Rigs
The main goal of TL081 Speech Processor circuit is to boost, shape and process your voice signal before sending it to the radio transmitter
Build Your Own 80M CW Transmitter from Scratch
Learn to build a simple 80M CW transmitter with crystal oscillator and parallel power amplifier. Complete circuit guide for amateur radio enthusiasts
Build Your Own Grenade AM Transmitter Circuit: A Complete Guide
The Grenade AM transmitter is a fascinating DIY electronics project that combines simplicity with effective radio frequency transmission.
Build Your Own 40M AM Transmitter: A Classic Radio Project
This blog post delves into the construction of a 40M AM transmitter. Perfect for hobbyists offers a fantastic hands-on experience with RF electronics.
The Poor-Man’s Transmitter: Building a Simple AM Radio Beacon from Vintage Electronics
The Poor-Man’s Transmitter: Building a Simple AM Radio Beacon from Vintage Electronics, uses a clever arrangement of 4011 CMOS gates to create AM Radio Beacon
NJM4558 Audio Compressor Circuit: Complete Schematic & Build Guide
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 […]
Building Steve Quest’s Simple AM Transmitter
This simple AM transmitter uses a crystal-controlled oscillator and transistor stages to generate and amplify a stable RF signal, then modulates it with audio through a transformer. Powered by 12V, it offers a practical introduction to radio transmission using basic, easily available components.
Building an FT8 Digital Interface – Dive into Digital Modes
This FT8 digital interface connects a computer to a transceiver using a USB sound card, audio transformers, and optocoupler-based PTT control. It enables clean audio exchange and safe isolation, allowing reliable weak-signal digital communication modes like FT8 through proper level control and synchronization.
Simple CW 74HC240 Transmitter using buffer IC
This simple CW transmitter uses a 74HC240 buffer IC as both oscillator and driver to generate a stable RF signal around 7.023 MHz. A crystal ensures frequency accuracy, while keying enables Morse transmission, making it a compact, low-power QRP project for beginners.