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	USCM \| Voices of Love and Freedom \| Boston, MA
		VLF helps students appreciate literature from around the world, develop their own voices as they learn to read and write, learn to use the values of love and freedom to guide their lives, and live healthy lives free of substance abuse and violence.
		VLF is also being implemented in Memphis, New York City, and other urban schools across the country.
		VLF has developed conflict resolution exercises that may be used to both analyze a story or in hypothetical situations where students are asked to solve personal conflicts that are similar to those they might encounter in their own lives.
	www.usmayors.org /USCM/best_practices/bp98/09_1998_Preventing_School_Violence30.htm (940 words)

	On the association of early/fast very low frequency perturbations with sprites and rare examples of VLF backscatter
		Very low frequency (VLF) data recorded in the midwestern United States are compared with sprite observations on three different dates of high sprite activity between 1995 and 2000.
		Sprites are frequently seen to be correlated with “early/fast” events: perturbations of the amplitude and/or phase of a VLF transmitter signal propagating through the storm region.
		The difference between the two data sets might be due to the relative location of the causative lightning along the VLF signal path (i.e., near transmitter or near receiver) in that mode coupling of the propagating VLF signal causes some perturbations to be undetectable at long distances from the disturbed region.
	www.agu.org /pubs/crossref/2006/2006JD007219.shtml (358 words)

	AAVSO: A Minimal Gyrator II VLF Receiver
		The Gyrator II VLF receiver is described in another section of the SID equipment.
		The Minimal Gyrator II receiver described here is an attempt to show a lower parts cost receiver for solar monitoring that would be a suitable school project.
		Although the Q of these capacitors is not as high as the polypropylene capacitors, they still provide sufficient selectivity for good tuning.
	www.aavso.org /observing/programs/solar/minimalVLF.shtml (815 words)

	Earth Songs
		If you have an internet connection you can now listen to a VLF radio anytime you wish.
		VLF signals from nearby lightning, heard through the loudspeaker of a radio, sound like bacon frying on a griddle or the crackling of a hot campfire.
		Participants build their own VLF radios and they can join a global network of monitoring stations that includes more than 1500 schools.
	science.nasa.gov /headlines/y2001/ast19jan_1.htm (1130 words)

	PC with soundcard used as VLF receiver
		To modify the VLF "RX-frequency", move the red "VFO" marker on the frequency scale of the spectrum plot or waterfall display in the main window.
		The VLF RDF antenna was deliberately placed in a noisy environment (indoors), so the ALPHA pulses were barely audible in the noise.
		With some luck, you may be able to receive VLF stations up to 40..44 kHz (to receive 48kHz is not possible because of the soundcard's anti-aliasing filter).
	www.qsl.net /dl4yhf/speclab/vlf_rcvr.htm (2444 words)

	“Early/slow” events: A new category of VLF perturbations observed in relation with sprites
		Analysis of subionospheric VLF transmissions, observed in relation with sprites, has led to the identification of a new category of VLF perturbations caused by the direct effects of tropospheric lightning on the overlying lower ionosphere.
		Analysis of broadband VLF sferic recordings, made with a two-channel receiver near the sprite producing storms, shows that the growth phase of an early/slow event coincides with the occurrence of complex and dynamic lightning action.
		We postulate that the long onset durations are due to secondary ionization buildup in the upper D region below the nighttime VLF reflection heights, caused mainly by the impact on sprite-produced electrons of sequential electromagnetic pulses radiated upward from horizontal in-cloud discharges.
	www.agu.org /pubs/crossref/2006/2006JA011960.shtml (333 words)

	Natural VLF Radio Home Page level two - Sounds of Space Weather - S. McGreevy, N6NKS
		A: Natural VLF (very-low-frequency) 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.
		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.
		The VLF Story: A story of my beginnings in VLF listening back in 1989 and subsequent travels to obtain my recordings.
	www.auroralchorus.com /natradio.htm (1151 words)

	Very Low-Frequency (VLF) Method
		Therefore, the high frequency of the VLF transmitters means that in more conductive environments, the exploration depth is quite shallow; for example, the depth of exploration might be 10 to 12 m in 25-Ωm material.
		VLF response is a maximum when the target strikes in the direction of the transmitter, falling off roughly as the cosine of the strike angle for other directions.
		Finally, the major disadvantage of the VLF method is that the high frequency results in a multitude of anomalies from unwanted sources such as swamp edges, creeks, and topographic highs.
	www.freewebtown.com /geophysics2/Vlf.html (1874 words)

	VLF Waves in the Foreshock
		The VLF waves observed in the foreshock of Venus have been analyzed in terms of polarization, intensity as a function of location within the foreshock, and dependence on solar wind plasma density /20, 21, 26/.
		VLF waves observed in the electron foreshock that is present upstream of planetary bow shocks appear to be a useful diagnostic of the energization processed that occur at the bow shock.
		Figure 5 indicates that the VLF waves in the ion foreshock are generated well downstream of where ion beams are expected to be present, rather they are observed where we might expect diffuse ions to be present.
	www-ssc.igpp.ucla.edu /~strange/vlf_upstream/vlf.html (6652 words)

	142 RIVAL: VLF waves
		VLF is the term for electromagnetic waves of up to about 25 KiloHertz frequency.
		VLF magnetic fields are detected by coils in which currents flow in proportion to core permeability, the number of turns and the field component along the coil axis.
		The signal strength is roughly proportional to the amplitude of the electric-field component parallel to the aerial, and to the aerial length.
	www.consciousness-centre.com /rival/1_tech/vlf1.htm (605 words)

	Very Low Frequency (VLF)
		VLF is useful for detecting lateral changes in subsurface electrical properties, and is used primarily for locating water bearing fractures in bedrock.
		VLF is often used in conjunction with EM, electrical and/or seismic methods for sighting high yield water wells and locating preferential contaminant pathways in bedrock, but VLF can be used as a stand alone method.
		Hager-Richter was hired to perform seismic refraction, EM-34 and VLF surveys to determine the depth of bedrock and detect a fracture zone that may have been acting as a preferential pathway for contaminant transport.
	www.hager-richter.com /vlf.htm (414 words)

	VLF Data Sheet
		Airborne VLF data are mainly used for the interpretation of large scale geological features such as faults and conducting rock units, although under favourable circumstances, smaller conductors such as those due to sulphide mineralization may be revealed.
		VLF data are regarded as an excellent, cost-effective complement to airborne magnetic data.
		As VLF stations are located at 100 Hz increments, the acceptance bandwidth around the nominal frequency is sufficient to accommodate modulation plus some offset without causing severe modulation noise.
	www.rmsinst.com /dshtvlf.htm (1143 words)

	VLF Electromagnetic Receiver
		VLF sensors can be installed on a wing tip, nose stinger, lower helicopter frame, or a towed bird.
		The VLF technique became practicable after the completion by the U.S. Navy and other powers of a network of powerful transmitters which were designed for communication with submarines.
		Measurements were carried out simultaneously at 3 frequencies, one in the VLF band (15 to 25 kHz), one in the LF band (200 to 400 kHz), and one in the MF band (550 kHz to 1.1 MHz).
	www.rmsinst.com /vt2.htm (1731 words)

	GEM Advanced Magnetometers l Products l Overhauser
		VLF surveying relies on radio signals that are broadcast from navigation stations around the world.
		VLF data can be plotted on the graphic display in real time.
		In addition, the Walking mode option allows magnetic and VLF surveys to be conducted simultaneously and with very little user intervention.
	www.gemsys.ca /prod_vlf.htm (304 words)

	2002 Budget Analysis: P&I, The Vehicle License Fee and The 2002-03 Budget
		Once the VLF owed is calculated using the 2 percent tax rate, the 67.5 percent tax reduction—or "offset"—is applied to the amount owed.
		The revenues from the VLF are allocated to cities and counties.
		The original VLF rate reduction legislation in 1998 included a paragraph governing VLF tax relief during periods in which insufficient moneys are available to pay for the General Fund backfill to local governments (see shaded box).
	www.lao.ca.gov /analysis_2002/2002_pandi/pi_part_5d_vlf_anl02.html (2062 words)

	Mainframes.com - VLF (Site not responding. Last check: )
		Virtual lookaside facility (VLF) is a set of services that can improve the performance and response time of applications that must retrieve a set of data for many users.
		VLF creates and manages a data space to store an application's most frequently used data.
		When the application makes a request for data, VLF checks its data space to see if the data is there.
	www.mainframes.com /vlf.htm (133 words)

	BASIC VLF SIGNALS
		The VLF radio signal is ducted to the receiver between the surface of the earth and layers in the ionosphere which reflect radio waves.
		When ducted over large distances, the VLF radio waves undergo a process called dispersion - that is the higher frequencies travel slightly faster than the lower frequencies.
		Under the right conditions, the VLF signal travels out away from earth and returns by traveling along a magnetic field line.
	image.gsfc.nasa.gov /poetry/inspire/basic.html (378 words)

	VLF (Site not responding. Last check: )
		VLF prior to World War II From the earliest days of radio after 1900, it was already well known that the frequencies below 100 kHz were capable of sending signals thousands of miles, day or night.
		VLF antennas have to be huge to transmit effectively.
		The third type of VLF antenna, "Goliath" is no exageration, since the one at Cutler ME consists of about 26 1000-foot high towers in two groups, covering a 2 sq mi peninsula on the Maine coast.
	members.aol.com /trekkspill/VLF.html (1136 words)

	Introduction to VLF radio emissions (Site not responding. Last check: )
		Unless you live in a remote wilderness area, natural VLF radio emissions are not heard without some effort and a lot of patients.
		If the entire VLF receiver station can be disassembled in less then 30 seconds then it might be ok to break it down and bring it in.
		It might be a good idea to think about remote VLF listening for high lightning incidence areas, such as in the state of Florida and other places in the world.
	www.home.pon.net /785/introduction.htm (440 words)

	PSP Global - VLF/Surge Generator Combination From HVI (Site not responding. Last check: )
		VLF AC Testing at.1 Hz is ideal for proof testing cable feeders, substation getaway runs, aerial insulated cable and URD cable runs.
		The VLF AC hipot test technique has also been found to be very effective for verifying workmanship of new splices and termination joints especially when done under emergency weather conditions trying to restore power to customer.
		VLF Technology is rapidly being adopted by the industry and is a good method to find weak cables before they fail.
	www.psp-global.com /vlf_surge_generator_combination_from_hvi.php (463 words)

	Spectrum Geophysical Services and Utility Location Services
		A very low frequency (VLF) investigation is well suited to the location of geologic faults (and approximating their attitudes), some types of geologic contacts, and buried conductive bodies including water-bearing faults.
		In a VLF investigation, the magnetic field components of the transmitted signal are measured, although the electrical field components can also be measured as required.
		Measurements of the electrical components are referred to as a VLF resistivity investigation (VLF-R).
	www.spectrum-geophysics.com /methods/mvlf.htm (207 words)

	VLF - Very Low Frequency AC Hipots - High Voltage, Inc.
		High Voltage offers a full line of VLF hipots from 25kVac to 200kVac with models capable of testing up to 50uF of load, cables from 1500 feet to 90 miles in length and the largest of generators and motors.
		A VLF hipot is a portable testing solution for XLPE, PE and EPR cables enabling utilities and industry to economically field test cables and other high capacitance electrical apparatus.
		For rotating machinery testing, a VLF hipot is a favored approach over the use of multi-ton series resonant systems.
	www.hvinc.com /vlf4060prd.htm (391 words)

	Very Low Frequency (VLF) — PARI WebSite
		Meteors burning up in the atmosphere, and even earthquake energy is thought to manifest itself in VLF energy at times.
		The balanced loop configuration was chosen to improve our immunity to lightning static noise by concentrating on receiving the magnetic component of the VLF signals.
		VLF is primarily a winter project in North America.
	www.pari.edu /telescopes/RadioTelescopes/vlf (417 words)

	Advanced VLF Signals
		The power grid radiates VLF radio waves at frequencies of 60 hertz and the harmonic multiples of that number.
		The sound is a background hum that is stronger the closer the receiver is to the lines and also stronger if the line voltage is higher.
		INSPIRE attempted to record the resulting VLF waves created by turning the electron gun off and on at various frequencies.
	image.gsfc.nasa.gov /poetry/inspire/advanced.html (663 words)

	Why VLF Hipot? - High Voltage, Inc.
		It has been known for years and now generally accepted by the entire cable industry that direct current hipot testing of XLPE cables is both substantially less effective than alternating current testing in determining the integrity of the cable, and damaging to the longevity of the cable (treeing effect).
		Studies have shown that VLF (0.1, 0.05, 0.02 or 0.01 Hz) systems produce the same dielectric stresses as power frequency tests at the same voltage without subjecting the cable to the harmful effects of dc polarization.
		Because of the technology employed, a sinusoidal VLF test set will cost a fraction of the cost of a traditional or resonant test set and be far more transportable than either one.
	www.hvinc.com /whyvlf.htm (352 words)

	Notes on Domestic VLF Reception
		Traditionally, high quality reception of VLF natural radio signals has involved driving or hiking out to remote locations far from civilisation, in order to find an environment free of pollution by artificial radio signals.
		Following a tip, I put in a second isolating transformer at the bottom end of the coax, so that the entire coax is floating, and this did away with that last bit of extra hum introduced by the direct connection.
		Sign up to the VLF Group discussion list for help and advice along the way, and to share your results with.
	www.abelian.demon.co.uk /vlf (3769 words)

	Very Low Frequency (VLF) Stations (Site not responding. Last check: )
		Because of that, few Radio Amateurs or shortwave listeners have ever heard VLF signals and most know very little about the large number of stations in that part of the spectrum, what those stations are used for, or the nature of VLF radio signal propagation.
		However, because VLF receivers and receiving antennas are easy to construct, the VLF spectrum attracts a small number of curious and sometimes very dedicated VLF listeners who want to learn more about this little-known and somewhat secretive part of the radio spectrum.
		Though some VLF stations have other purposes, the primary function of most VLF stations is to communicate with submerged military submarines or help them navigate underwater.
	www.smeter.net /stations/vlf-stations.php (926 words)

	Very Low Frequency (VLF) - United States Nuclear Forces
		Very Low Frequency (VLF) communications transmitters use digital signals to communicate with submerged submarines on at frequencies of 3-30 kHz.
		The Navy shore VLF/LF transmitter facilities transmit a 50 baud submarine command and control broadcast which is the backbone of the submarine broadcast system.
		The Very Low Frequency (VLF) transmitters are old vacuum tube technology with an average age of 37 years.
	www.fas.org /nuke/guide/usa/c3i/vlf.htm (649 words)

	Spaceweather Sounds - Natural VLF Radio - Stephen P. McGreevy
		VLF Soundbites - Audio Files (mp3/wav) Page One of Three Pages
		The VLF Story (first written in 1995, updated 2007
		Central Manitoba, Canada is the truly best place, in late summer when it is still warm, to see gorgeous aurora, and much closer to travel to than distant Alaska.
	www.spaceweathersounds.com (350 words)

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