Simple series modulated AM QRP HF Transmitter

Check out this nifty beginner-friendly radio project: a Simple Series Modulated AM QRP HF Transmitter! It’s a low-power HF (high-frequency) transmitter using series modulation to send AM (amplitude modulated) audio signals — great if you’re into QRP (low-power) operation or want a hands-on build to learn RF basics. Perfect for homebrew enthusiasts and DIY radio builders alike. Dive into the details and schematic here: https://vu3dxr.in/simple-series-modulated-am-qrp-hf-transmitter/

Simple series modulated AM QRP HF Transmitter

Simple mic compressor using 3 Transistors for HF rigs

Simple mic compressor using 3 Transistors for HF rigs: Simple mic compressor using 3 Transistors is a effective, compressor circuit that can be used to improve the dynamic range of a microphone signal.

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).