Here are some sites where natural Radio and VLF enthusiasts hang out.

Radio Waves Below 22 Hz.

This site, started and maintained by Renato Romero, IK1QFK, is the place to find in depth research and technical information on Natural Radio and VLF topics. There are many in-depth technical articles on equipment and reception techniques, as well as reports on various signals and other interesting topics.

http://www.vlf.it/

Live VLF Natural Radio

This site consists of a collection of live natural radio streams of the VLF band as well as a variety of data from those streams. There are some stereo streams also, with two separated sites feeding the stream.

http://abelian.org/vlf/

SolarHam.net

This site by Kevin, VE3EN, has loads of data relating to the current sunspot cycle. There is an amazing amount of Real-Time and archived data and a message board, as well as 6-meter propagation data. If you need to find out anything about what’s goiong on on the sun, this is the place.

http://www.solarham.net

University of Iowa Radio & Plasma Wave Group

The Radio and Plasma Wave Research Group at The University of Iowa Department of Physics and Astronomy is led by Professor Donald Gurnett. They are one of several space physics research groups in the department with a heritage, including the very first successful U.S. orbital space launch of Explorer 1 in 1958 carrying Professor Van Allen’s cosmic ray experiment. This group is responsible for the first recordings of Chorus from inside the Van Allen Belts by NASA’s Radiation Belt Storm Probes (RBSP). The RBSP EMFISIS Waves Instrument Science Team is based within this group.

http://www-pw.physics.uiowa.edu/

INSPIRE

The INSPIRE Project, Inc. is a non-profit scientific, educational corporation whose objective is to bring the excitement of observing natural and manmade radio waves in the audio region to high school students.

http://theinspireproject.org/

Longwave Club of America (LWCA)

The Longwave Club of America was organized in January, 1974 to promote monitoring and experimentation on frequencies below the AM broadcast band. Such activities have come to include hearing and identifying navigational beacons, recording and analyzing natural radio emissions at very low frequencies, transmitting under low power rules in the 1750 meter band, and later on other frequencies where such ‘Part 15’ activity is also permitted.

http://www.lwca.org/