Instructables Post on Building a Discone Antenna
A Discone is a wideband antenna that is a great starting antenna for general RTL-SDR use. Over on instructables.com, user cyfus has created an instructable showing how to build a 55 MHz+ home made discone antenna for his RTL-SDR dongle. His instructions show how to build it out of parts and tools sourced entirely from hardware and electronics stores.
Using this antenna cyfus was able to receive signals from 25 MHz to around 900 MHz.
This home made antenna looks like umbrella hit by a lighting! 🙂