An off-the-shelf RTL-SDR unit.

downconverter

An off-the-shelf RTL-SDR unit.

TT7 High Altitude Balloon: The APRS iGate

RTL-SDR Fun - John's Tech Blog

Some photos of my RTL-SDR and its melted chips for your amusement

SDR Radio - 5 Best Software Defined Radios - File Edge

WSPR

Quick Start Guide

RTL-SDR - Hacker Warehouse

OTA: LimeSDR on the Traverse Ten64, LimeRFE Production Update, and

Meterk Mini-Whip 10Khz-30Mhz 2Pcs Medium And Shortwave Rtl‑Sdr

mixer

A 3D Printed Stand for Generic MCX RTL-SDR Dongles

VHF planesandstuff