Aurora photo taken by S. P. McGreevy in northern Manitoba, Canada on 23 August 1996.
The WR-4b receiver's VLF vertical whip antenna is attached to van on its rear door. This is the VLF receiving system and expedition "accomodation" I have used for the past 5 years.
A: Natural VLF Radio - also called "Natural Radio" - are audio-frequency radio signals of Earth in the approximately 200 Hz to beyond 10,000 Hz (10 kHz) spectrum which are not man-made but occur naturally in nature. Most of the best phenomena are heard between 400 Hz and 5 kHz.
Interest in naturally-occurring VLF radio phenomena such as "whistlers" and "chorus" has enjoyed a rapid resurgence during the 1990's on the part of academic research via orbiting space-probes and ground-based monitoring efforts, and also notably amongst amateur hobbyists world-wide thanks to easy availability of sensitive receiving equipment. As Solar-Cycle 23 begins, we're seeing increased solar-activity spawn greater amounts VLF phenomena here on Earth, as it is activity on the Sun and its Solar Wind that help create the great variety of VLF phenomena that we can monitor - whether for study or simply for enjoyment.
Many people who are not really "radio nuts" or "techies" but who love nature have listened to Natural Radio either live or recorded and have called it the "music of Earth itself." To listen and enjoy Natural Radio, the audio-frequency radio waves must be converted directly to sound via a receiver like the commercially available WR-3E.
Lightning storms, Earth's magnetic-field (the Magnetosphere), and the Aurora Borealis and Australis (Northern & Southern Lights) all produce an amazing variety of electromagnetic "sounds," such as sferics (lightning-stroke static), tweeks, Whistlers of countless variety, the incredible "Chorus" chirping, barking and squawking radio "sounds" produced by the the Sun's solar-wind hitting Earth's magnetic-field; various kinds of "Hiss"; bizzarre "wavering-tone" emissions, and other endless variety of fascinating radio sounds to listen to.
Natural VLF radio signals tell a great deal of what is happening with Earth's "near-space weather," that is, what is going on between the Sun and Earth. Invisible weather to our eyes but just as wild and stormy at times as the weather "down here."
Auroral curtains photographed at 0500 UTC on 23 August 1996 in Manitoba, Canada during my SOLAR-MINIMUM VLF RECORDING EXPEDITION. Photo by Stephen P. McGreevy
Many listeners to natural VLF radio note how the majority of these recordings of Earth's beautiful Natural VLF Radio sounds closely resemble biological/vocal sounds made by birds, frogs, whales, seals, etc. (or sci-fi sound effects). As we begin a new Solar-Cycle (#23) and see increasing numbers of sunspots and associated magnetic-storms and disturbances here on Earth, we're already seeing an upsurge in naturally-occurring VLF phenomena. Between now and the sunspot peak in the years 1999 - 2001, we're entering a fabulous time once again to listen to radio signals below 10 kHz.
WR-3 & WR-3E VLF Receiver Listening Guide: A good source to learn more, and how you can listen yourself!
WR-3 and WR-3E VLF receiver information sheet: (I get MANY inquiries about these receivers, so I've moved this link into a more accessible place here on this page)
NEW!:
VLF LISTENER'S HANDBOOK (Text-only version) I have combined the text portions only (no images or hyperlinks) of the THE VLF STORY (see link below too for entire version); The WR-3/3E LISTENING GUIDE; plus a sheet describing the various SOUNDS OF VLF PHENOMENA. At the end of this document, I'll be including miscellaneous VLF discussions gleaned from my e-mail correspondence to other listeners - that section will continuously expand in time. Save to your hard-drive and read/print off-line with your web browser. Chock full of about 50(+) pages of information all about Natural VLF Radio (145K of HTML text as of October 1997)
This amazing and fascinating account of Bill Hooper's experience in a remote location in California's Death Valley is mentioned in brief in THE VLF STORY by Stephen P. McGreevy. The original article appeared in the Longwave Club of America's monthly bulletin, The Lowdown in February 1993, pp. 22 to 40. I feel it MUST appear in this Web site in its entirety since it ties in so well with my own expeditions and experiences, though I have not (usually) experienced the amount of extreme difficulties Bill went through --and--I sure feel I travel extremely "light and simple" now after reading Bill's extensive list of supplies he brought along and the problems he was plagued with, yet my own van seems to always be quite full of supplies and equipment too when I head out to capture Mother Natures incredible natural radio shows!
Omega - End of an Epoch chronicles the last half-minute of the world-wide Omega Radio Navigation System which terminated operations at 0300 UT on 30 September 1997. Omega could be heard as a shrill, high-pitched beeping sound at the high audio frequency end of the Natural VLF Radio Band. Omega stations A through H broadcast from 10.2 - 13.6 kHz. There is also information on the Russian ALPHA radionavigation system still in operation.
Photo of a WR-3E VLF receiver clamped to a camera tripod and another of Steve McGreevy with WR-3E and Marantz PMD-221 recorder in the Warner Mountains near Lakeview, Oregon
Still more about Natural VLF Radio...:
