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Topic: Ultra low frequency

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Super low frequency

Very low frequency

Extremely high frequency

Low frequency

Very high frequency

SHF

Ultra high frequency

Longwave

Mediumwave

Microwave

Shortwave

Taos Hum

Communication with submarines

Skin effect

Palestine (region)

	Ultra Low-frequency Pulse Generator RR-77
		The "Schumann Resonance" is a resonance frequency that exists in the Earth's "electromagnetic" cavity; i.e.
		The lowest-frequency ?iand highest-intensity ?jmode of the Schumann Resonance is at a frequency of approximately 7.83Hz.
		We substantiate that there are many effects when the frequency of 7.83Hz is generated artificially.
	www.acoustic-revive.com /english/rr77/rr77_01.html (502 words)

	Ultra-low Natural Frequency Vibration Isolatin Workstation - MK26 Series
		Kinetic Systems manufactures the system utilizing the Minus K patented negative stiffness vibration isolators in order to provide a compact, passive Vibration Isolation Workstation with ultra-low natural frequencies, higher internal structural frequencies, and excellent vertical and horizontal isolation efficiencies.
		The Minus K vertical isolator uses a stiff spring and negative-stiffness mechanism to achieve a low net vertical stiffness without affecting the static load supporting capability.
		Adjusted to a 1/2 Hz natural frequency, the workstation achieves 93% isolation efficiency at 2 Hz, 99% at 5 Hz and 99.7% at 10 Hz.
	www.kineticsystems.com /page471.html (225 words)

	Filter for ultra low frequency - Electronic Circuits Projects Diagrams Free
		The frequencies overlap, but the one is always 2 or 3 times higher than the other one.
		Ultra low frequency to me is in the milli-hertz range.
		You can't really filter frequencies of this range, not using typical filter topologies, a better understanding of the exact voltage and time domain you're talking about is really required to answer the question.
	www.electro-tech-online.com /electronic-projects-design-ideas-reviews/25000-filter-ultra-low-frequency.html (450 words)

	Ultra low noise frequency generator producing the sum of plural signal sources - Patent 5625324 (Site not responding. Last check: )
		frequency summing means responsive to the first and second sum outputs for providing a third output having a frequency equal to the sum of the frequencies of the first and second outputs.
		Frequency multiplying circuits decrease the signal-to-sideband phase noise power ratio by a factor of 20 log(N), where N is the frequency multiplication factor.
		The difference frequency signal from mixer 86 is a DC voltage that is dependent on the phase difference between the two nominally equal frequency mixer inputs and is used as the control signal to phase lock oscillator 70D.
	www.freepatentsonline.com /5625324.html (5265 words)

	Ultra low frequency - Wikipedia, the free encyclopedia
		Ultra Low Frequency (ULF) is the frequency range between 300 hertz and 3000 hertz.
		Some monitoring stations have reported that earthquakes are sometimes preceded by a spike in ULF activity.
		Researchers are attempting to learn more about this correlation to find out whether this method can be used as part of an early warning system for earthquakes.
	en.wikipedia.org /wiki/Ultra_low_frequency (148 words)

	UltraSonics.com
		In ultrasonics, the frequency of under 30HZ is defined as “ultra low frequency”, and the frequency of over 20KHZ is defined as the “ultrasonic”.
		When a Frequency Sweep Modulation is effectuated, Ultrasonic Generators emit an output frequency that is modulated around a central, adjustable frequency.
		Frequency Sweep Modulation allows for optimum cleaning through Ultrasonics in a myriad of of applications, which cannot be addressed by any other single method.
	www.ultrasonics.com /new/whatis.html (1010 words)

	Wavelength of the Longest Electromagnetic Waves
		The electromagnetic spectrum is a continuum of all electromagnetic waves arranged according to frequency and wavelength.
		Since frequency and wavelength are inversely proportional (v = fλ, for electromagnetic waves c = fλ), the name "ultra low frequency"is equivalent to "ultra long wavelength" -- although nobody refers to them as such.
		ULF waves seem to have extraterrestrial sources (they seem to "result from interactions between plasma emitted from the sun (solar wind) and the Earth's [magnetic] field").
	hypertextbook.com /facts/2001/RachelShapiro.shtml (399 words)

	Ultra low noise frequency generator producing the sum of plural signal sources - US Patent 5625324 (Site not responding. Last check: )
		Ultra low noise frequency generator producing the sum of plural signal sources
		The frequencies of N oscillators are summed to provide a signal generator output signal.
		The signal generator is implemented to assure independence of the oscillator noise contributions, with phase locking the oscillators to a common frequency for ease of spurious signal control.
	www.patentstorm.us /patents/5625324.html (158 words)

	Ultra high frequency - Wikipedia, the free encyclopedia
		Ultra high frequency (UHF) designates a range (band) of electromagnetic waves whose frequency is between 300 MHz and 3.0 GHz.
		Waves whose frequency is above the UHF band fall into the microwave or higher bands, while lower frequency signals fall into the VHF or lower bands.
		Modern mobile phones also transmit and receive within the UHF spectrum, and UHF is widely used for two-way radio communication (usually using narrowband frequency modulation, but digital services are on the rise) by both public service agencies and the general public.
	www.higiena-system.com /wiki/link-UHF (1155 words)

	Radio frequency - Wikipedia, the free encyclopedia
		Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna.
		The ELF, SLF, ULF, and VLF bands overlap the AF (audio frequency) spectrum, which is approximately 20–20,000 Hz.
		Frequencies from 216 to 450 MHz were sometimes called P-band: Previous, since early British Radar used this band but later switched to higher frequencies.
	en.wikipedia.org /wiki/Radio_frequency (467 words)

	Physical activity is a major contributor to the ultra low frequency components of heart rate variability -- Serrador et ...
		Physical activity is a major contributor to the ultra low frequency components of heart rate variability -- Serrador et al.
		Mean gain for those frequencies at which coherence was greater than 0.5 (lower panels, note the change in scale for VLF, LF, and HF frequency bands).
		Circadian rhythms of frequency domain measures of heart rate variability in healthy subjects and patients with coronary artery disease: effects of arousal and upright posture.
	heart.bmjjournals.com /cgi/content/full/82/6/e9 (3753 words)

	Astrology3D
		The frequencies that he has had his successes with are generally very high vibrations that pass through all matter and are invisible to the human eye.
		These very long waves of extremely low frequency are similar to the high frequency waves that we use and take for granted in our daily lives in that they pass through all matter as well.
		As the planets continue their cyclical journey around the Sun, the ultra low frequency pattern of the solar systems unified field is focused here on earth, the pattern evolves and interacts with the reference pattern infused into the infant at birth in the measurable and predictable way that the science/art of astrology indicates is significant.
	www.astrology3d.com /tv/whyitworks.html (798 words)

	Ghosts created by low frequency sounds
		His first thought was that there might be low frequency sound waves coming from somewhere in the laboratory -- subsonic sounds that can be seen (in the form of surrounding vibrations) but not heard.
		Tandy believes that the low frequency sound also caused his late-night spectral visitation: the cold chills, the sense of paranoia and distress, the hallucinatory figure glimpsed creeping in the shadows.
		The ancient architects of these tombs may not have understood infrasound frequencies and Helmholtz resonance, but spookiness was a desirable feature for a tomb, for the purpose of instilling reverence for the dead and discouraging grave-robbers.
	meta-religion.com /Paranormale/Ghost/ghosts_created_by_low_frequency.htm (1159 words)

	Real-Time Control of Neutrophil Metabolism by Very Weak Ultra-Low Frequency Pulsed Magnetic Fields Biophysical Journal ...
		Utilizing fluorescence microscopy, we have shown in real-time, on the single cell level, that the system is sensitive to externally applied periodically pulsed weak magnetic fields matched in frequency to the metabolic oscillation.
		The higher frequency NAD(P)H dynamics is absolutely determinant for the polarized and motile state, in that we have never found spherical or non-adherent cells to exhibit 10- or 20-s period NAD(P)H oscillations.
		However, a possible drawback is that, as a consequence of relatively high conductivities, low frequency electric fields are severely attenuated in biological tissues.
	www.findarticles.com /p/articles/mi_qa3938/is_200505/ai_n13636277 (758 words)

	HF and Lower Frequency Radiation - Introduction
		Also there is less frequency "room" in the EM spectrum for these low frequencies than in the higher frequency bands.
		The actual frequency used within the HF band for skywaves depends on the properties of the ionosphere, which are highly variable.
		HF and lower frequencies are limited by the need for large antennas, especially the very low frequencies.
	www.weather.nps.navy.mil /~psguest/EMEO_online/module3/module_3_1.html (1661 words)

	Ultra Low Power - Frequency Asked Questions (Zarlink Semiconductor)
		An ultra low-powered converter chip designed into a digital microphone not only contributes to improved sound quality for consumers, but also lowers design costs for manufacturers by reducing complex external components.
		Ultra low-power RF applications are usually those where the radiated power is under 1 milliwatt and maximum ranges are around 10 meters in free air.
		Ultra low-power technology will support advances that contribute to better care, increased convenience for patients and doctors, and lower healthcare costs.
	ulp.zarlink.com /faq/index.htm (1397 words)

	Schumann Resonance at The University of Iowa
		The resonant frequency of the cavity falls in the ultra-low frequency (ULF) and extremely low frequency (ELF) bands in the range of 5–50 Hz, and depends on several factors, including the electrical parameters of the atmosphere, and the state (height, ionization level) of the ionosphere.
		The amplitude of the resonances decreases with frequency.
		Such low frequencies suffer very low attenuation in the atmosphere and penetrate significant distances underground and into the ocean.
	www.iihr.uiowa.edu /projects/schumann/Index.html (1460 words)

	What is ULF?
		Only the extremely low frequency portion of this signal survives the transfer through the surrounding earth.
		Slow moving ionic water seeping to cracks opened up by the fracturing of rocks near the surface (Dilatancy), and the "moving conductor in a magnetic field" generates an ULF magnetic field.
		There is a growing body of evidence that indicates strong connections between ULF waves and earthquakes (US, Japan, Russian, French).
	www.quakefinder.com /what_is_elf.htm (257 words)

	Darcy Karakelian's Homepage (Site not responding. Last check: )
		Ultra-low frequency electromagnetic measurements associated with the 1998 Mw 5.1 San Juan Bautista, California earthquake and implications for mechanisms of electromagnetic earthquake precursors, Tectonophysics.
		Analysis of ultra-low frequency electromagnetic field measurements associated with the 1999 M 7.1 Hector Mine earthquake sequence, Bull.
		A study of ULF magnetic field measurements in association with creep events along the San Andreas fault, Eos Trans.
	pangea.stanford.edu /~darcy/publications.html (242 words)

	Radio and Microwave Frequency Bands
		The Federal Communications Commission (FCC) regulates frequency use by setting specifications for transmit frequency, power, bandwidth, modulation, and location, to name a few, and requires a license for many uses.
		Frequency tolerance for Ka band radars typically ±100 MHz.
		In the early days of radio it was easier to measure wavelength than frequency.
	www.altair.org /labnotes_RadioBands.html (249 words)

	Yorkville Sound: Real Gear. Real People
		The variable high frequency cutoff is adjustable from 90 to 150 Hz to trim the subwoofers low-pass filter to suit whatever full range cabinets are being used with this sub.
		A low-frequency tunable bass boost adjustable from 45 to 90 Hz has been included to allow subtle customizing of the bass character.
		Dual bulb CTL circuit protection protects the 1.4-inch aluminum diaphragm horn drivers to ensure the YX15 cabinets' high frequency horn will continue to function, without damage, during typical overload conditions.
	www.yorkville.com (1347 words)

	Crystal and frequency control glossary - U
		Based on the GSM (Global System for Mobile communication), UMTS, endorsed by major standards bodies and manufacturers, is the planned standard for mobile users around the world by 2002.
		Frequency responses other than the main, or desired response, which the crystal elements have.
		If you would like us to suggest a definition for our crystal and frequency control glossary, please use our contact form or email us at info@icmfg.com to see how you may benefit from using International Crystal's frequency control products and services.
	www.icmfg.com /crystalglossaryu.html (213 words)

	TelecomPie.com
		Such frequencies account for the following parts of the spectrum shown in the table below.
		The identity of the original inventor of radio, at the time called wireless telegraphy, is contentious...
		Radio frequency, or RF, refers to that portion of the electromagnetic spectrum...
	www.telecompie.com /radio/frequency.html (270 words)

	Low Frequency Anomalies: What is ULF?
		Researchers have believed for some time that there is a correlation between ULF magnetic field fluctuations and seismic activity.
		Below are some notable examples of ULF signal activity collected before and after earthquakes.
		A remarkable collection of ULF signal data was observed by Tony Fraser-Smith*, a Stanford professor, in conjunction with the magnitude 7.1 Loma Prieta earthquake.
	www.quakefinder.com /fppt/LowFreqAn.htm (496 words)

	Frequency of the Lowest Electromagnetic Waves
		He was describing pulsations of the geomagnetic field, with an amplitude of roughly 0.2 % of the background field, and frequencies in the range between 30 mHz and 3 mHz.
		An interesting observation to note is that those sources that refer to micropulsations as part of the ULF band are international (e.g.
		Australia, Germany, Finland, and Denmark), while those sources stating that the ULF range has a higher frequency than ELF range are primarily from the United States.
	hypertextbook.com /facts/2001/ElizabethWong.shtml (536 words)

	References
		Anderson, B. J., ULF signals observed near the magnetopause, in The Physics of the Magnetopause, Geophysical Monograph series, edited by B. Sonnerup, M. Thomsen, and P. Song, Washington, D.C.: American Geophysical Union, in press, 1994b.
		Le, G., and C. Russell, The morphology of ULF waves in the Earth's foreshock, in Solar Wind Sources of Magnetospheric Ultra-Low-Frequency Waves, Geophysical Monograph 81, edited by M. Engebretson, K. Takahashi, and M. Scholer, Washington, D.C.: American Geophysical Union, 87, 1994.
		Walker, A. Ruohoniemi, K. Baker, R. Greenwald, and J. Samson, Spatial and temporal behavior of ULF pulsations observed by the Goose Bay HF radar, J. Geophys.
	www.agu.org /revgeophys/engebr01/node8.html (2096 words)

	Minus K® Releases New Ultra-Low Frequency Vibration Isolation (Site not responding. Last check: )
		The net vertical stiffness is made very low without affecting the static load-supporting capability of the spring, the company reports.
		(A beam-column behaves as a spring combined with an NSM.) The result is a compact passive isolator capable of very low vertical and horizontal natural frequencies and very high internal structural frequencies, according to the company.
		Minus K claims its isolators (adjusted to 1/2 Hz) achieve 93% isolation efficiency at 2 Hz; 99% at 5 Hz; and 99.7% at 10 Hz.
	www.electronicsweb.com /content/news/article.asp?docid={9F7F3B97-8D19-49A6-A62F-59C1F8EECD0E} (374 words)

	Novel Materials for Ultra-Sensitive Low-Frequency Magnetometers (Site not responding. Last check: )
		Combinations of the thin-film materials and deposition conditions that prove the greatest potential for substantially increasing the sensor's signal-to-noise ratio (SNR) will be chosen for the Phase II prototype development.
		The goal of the program is to produce a magnetic-field sensor element which resolves sub-nanoTesla field perturbations at milliHertz frequencies.
		The emerging technology of spin-dependent tunneling devices is ideal in that it has great potential for increasing SNR at low frequency and its inherent attributes include: low power, small size, low cost, IC compatiblility, ruggedness, standard microelectronics processing, and broad-band frequency resolution.
	www.navysbir.com /05_s/69.htm (199 words)

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