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Topic: Groundwave

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	[No title]
		Because of its poor groundwave coverage, it was considered to be all but useless, and was far removed from the wavelengths amateurs had used prior to 1912.
		Forgotten in the "cult of the groundwave" was the fact that not all of a station's signal is groundwave -- some of it does indeed travel "through the air".
		Unlike the groundwave signal, which is unaffected by the sun, and has the same strength day and night, the strength of the reflected skywave signal is variable, and usually was too weak to be readily detected by the primitive receivers then in use.
	www.oldradio.com /archives/general/building_am_band.292 (11525 words)

	Groundwave
		The use of aerial amplifiers is not always recommended as they tend to increase the amount of received noise or give you so much signal that they overload the input to your receiver, resulting in stations appearing in odd places and sometimes mixing together.
		It should be noted that 'groundwave' signals only apply to the long and medium wave bands. “Groundwave” implies that a signal is travelling along the ground, or at least not much above rooftop level.
		Groundwave signals propagate along the air-earth boundary to cover the intended service area, and are attenuated in direct relation to the operating frequency.
	www.skywaves.info /index.php?entityType=HTML&id=17 (353 words)

	Communications Media Center at New York Law School
		The distance to the 500 mV/m groundwave contour of the 1 kW station is determined by the use of the appropriate curve in § 73.184.
		The groundwave field strength is considered to be that part of the vertical component of the electric field which has not been reflected from the ionosphere nor from the troposphere.
		The curves show the variation of the groundwave field strength with distance to be expected for transmission from a vertical antenna at the surface of a uniformly conducting spherical earth with the groundwave constants shown on the curves.
	www.nyls.edu /cmc/uslaws/part73a.htm (5641 words)

	Radio Netherlands Worldwide - Independent thinking, independent voice - English - Long Distance MW Listening: ...
		The groundwave, as its name implies, travels along a path close to the earth's surface.
		Groundwave propagation is heavily dependent on the frequency, with low frequency signals travelling greater distances.
		Firstly there is a region about 50-100 miles from a transmitter (Figure 4) where the groundwave and the skywave signals are received with roughly equal (but varying) strength, leading to severe distortion.
	www.radionetherlands.nl /features/media/practical/mwpropagation.html (1162 words)

	NVIS
		Groundwave propagation occurs when the receiving station is sufficiently close to the transmitting station, and is able to receive the portion of the transmitting station's signal which clings to the ground.
		The range of groundwave propagation varies with the type of antenna at the transmitting station, the characteristics of the ground between the transmitting station and the receiving station, and other factors.
		For areas which are within the groundwave range of the transmitting station, the ground-wave's presence may interfere with the reflecting skywave.
	www.emcomm.org /antenna/nvis.htm (2506 words)

	GRoundwAve Propagation Predictions
		GRAPPLE – GRoundwAve Propagation Predictions for the Littoral Environment – is applicable between 10 kHz and 30 MHz.
		It uses the ITU-R groundwave model (GRWAVE) for the underlying calculations, and is able to account for mixed land/sea paths by employing Millington's method.
		The groundwave model of propagation tends to be extremely stable.
	www.cpar.qinetiq.com /grapple.html (306 words)

	Computer Assisted Radio Monitoring
		The distance a groundwave is able to travel depends upon the transmitter power, frequency, antenna pattern, and the earth’s conductivity along the path of the signal.
		Groundwave propagation provides a broadcast station with reliable, stable coverage to its target audience, and radio station engineers optimize the antenna system to ensure the best delivery of that groundwave signal.
		At night, however, because of the recombination that occurs in the D layer, and the sharp reduction in mediumwave signal absorption that results, many stations must reduce their power so that they do not interfere with other stations.
	www.popular-communications.com /14Propagation.html (539 words)

	Elephant Ventures: Internet marketing, technology strategy and web development. (Site not responding. Last check: 2007-10-20)
		groundwave™ is an e-mail marketing service that allows you to create, send and measure permission-based e-mail marketing campaigns.
		groundwave™ enables you to grow your business and establish strong relationships with your customers while spending less time and money.
		When you sign up for a free groundwave™ trial, no payment or credit card information is required until you are completely satisfied with the service and have decided to sign up.
	www.elephantventures.com /emailmarketing.php (644 words)

	Why Did WABC Have Such a Great Signal?
		Groundwave signals hug the surface of the earth.
		For the strongest groundwave coverage, electrical lengths in excess of 1/2 wave (180 degrees) are desirable.
		In fact, 5/8 (225 degrees) is considered optimum, because it produces the maximum possible groundwave (or horizontal lobe) from a single vertical radiator.
	www.musicradio77.com /transm.html (1669 words)

	The Classic Vertical
		The groundwave hugs the earth, and the skywave radiates up toward the ionosphere and then bounces down to earth hundreds of miles away (if conditions are favorable).
		For example, if all of the radials are on the north and east side of the antenna, it will radiate slightly more power toward the south and west.
		However, this is not recommended for local broadcasting, because grouping the radials together increases the amount of energy radiated toward the sky and decreases the intensity of the groundwave.
	members.tripod.com /hlrinternational/id7.html (609 words)

	Re: Why 5/8 (Site not responding. Last check: 2007-10-20)
		finally in the am broadcast environment, on a clear channel a station's night-time coverage is limited by self-fading (interference between groundwave signals and skywave signals).
		as the distance from the transmitter increase the groundwave signal steadily decreases while the skywave signal is relatively constant or at least a much slower rate of decrease.
		at around 50 miles radius the 2 signals are typically about equal and massive fading occurs because of the rapidly changing phase and amplitude of the skywave signal and the combination with the groundwave signal.
	www.antennex.com /storage/atheory/_atheory/0000001f.htm (386 words)

	Hard-Core-DX.com: Groundwave propagation on SW (Site not responding. Last check: 2007-10-20)
		Hard-Core-DX.com: Groundwave propagation on SW Groundwave propagation on SW Thursday, August 21 2003
		(i.e.: groundwave on SW will be around 100 kilometers and line-of-sight on FM would be only 80 kilometers).
		I don`t know why but I think it would be VERY interesting to hear a fade-free signal on SW - for me shortwave is synonymous with fadings, but I know there is groundwave on SW.
	archive.hard-core-dx.com /channels/hcdx/2003-08/20030821143056805.html (137 words)

	Radio Propagation by Diffraction Over an Obstruction
		When there are two radio antennas located on or near the Earth's surface propagation can ordinarily occur between them by groundwave.
		When the radius of curvature is not small the waves pass over the curved top of the obstruction via groundwave.
		Depending on type of terrain, it may occur that path loss due to diffraction is less than the groundwave loss which would occur if the obstacle was removed.
	www.smeter.net /propagation/diffrac1.php (866 words)

	Building the Broadcast Band
		Service Regulations of the 1912 London International Radiotelegraph Convention, a choice band of wavelengths, from 600 to 1600 meters (500 to 187.5 khz) was appropriated primarily for government use.
		The 485 wavelength--with its better groundwave coverage--was probably seen as the more important development, and a greater public service, than the mere entertainment being sent out on 360.
		Until the development of affordable precise frequency control, plus directional antennas suitable for use on the broadcast band frequencies -- both a full decade away -- the only tools for preventing heterodyning on a common wavelength were wide separation of stations, timesharing, plus reduced nighttime powers and daytime-only operation.
	www.oldradio.com /archives/general/buildbcb.html (12359 words)

	Events Calendar
		Founded in 1999, groundwave is dedicated to the performance of new music and masterworks of the American avant-garde tradition.
		Recent performances organized by Groundwave have focused on solo piano works, electro-acoustic music, and dance-music collaboration.
		groundwave members have presented their work throughout the U.S. at venues such as the Tanglewood Festival, Williamsburg Arts Nexus, Music2003 Festival (Cincinnati), The Crow Collection (Dallas), and The Construction Company.
	www.theconstructioncompany.org /pages/ec04.html (920 words)

	Groundwave Propagation vs. Pathlength and Frequency for Various Terrains
		Groundwave Propagation vs. Pathlength and Frequency for Various Terrains
		Reference field strength for groundwave prediction is 300 millivolts per metre at a distance of 1 km from a transmitter which radiates 1 kilowatt from a short vertical antenna over a flat lossless ground, subject to the condition that the ground-path distance is greater than 3 or 4 wavelengths.
		Above 3.5 MHz in daylight and below 10 MHz at night, at distances greater than the radio horizon, ionospheric propagation may be as strong as or stronger than the groundwave.
	www.smeter.net /propagation/grndwav3.php (1028 words)

	Target DX 11/8/2002
		A - For most stations, there is an area of reliable daytime groundwave coverage, and a smaller area of nighttime groundwave coverage, even though the station has a larger overall combined coverage area at night.
		Outside of the nighttime groundwave area is another area where there is a combination of both groundwave and skywave.
		In Gordon Nelson's original loop construction article he describes being able to use the altazimuth feature to null the daytime groundwave signal component of a local down to the point where the predominant audible signal was in fact skywave reflection (well within the primary groundwave contour).
	www.nrcdxas.org /articles/tgt1102.html (1491 words)

	[cmc-users] MUSICIRCUS
		Since your mail reader does not understand this format, some or all of this message may not be legible.
		groundwave was formed in 1999 for the purposes of exploring sound and performance in intimate settings, and is dedicated to the promotion of new music and collaboration with artists in a variety of disciplines.
		A musicircus is an event that was conceived by John Cage, and designed for any number of musicians prepared to perform in the same place.
	www.music.columbia.edu /pipermail/cmc-users/2003-February/000089.html (307 words)

	SPACE-TALK - Is there a bettter way of searching for other life?
		I seriously doubt if there is enough signal strength being emitted by TV to be intercepted by another planet, considering the signals are horizontally polarized to maximize groundwave coverage.
		HF (3 Mhz to 30 Mhz) is also pretty much groundwave until you get above 7 Mhz when skywave (F-2) kicks in (better know as "skip" to CB'ers).
		In theory, if there were some "leakage" in those bands, it would be so small as to be un-detectable.
	www.space-talk.com /ForumE/showthread.php3?postid=18429 (864 words)

	C. Crane Company - Sky-Wave Radio (Site not responding. Last check: 2007-10-20)
		Sky-wave propagation takes place between sunset and sunrise - in other words, at night, and it's the flip side to the groundwave propagation used to transit during the day.
		During the day, groundwave propagation is preferable because the radiation from the sun causes so much ionization that radio signals sent into the air are just absorbed into the atmosphere.
		When atoms in the D region of the ionosphere are ionized, you end up with free electrons and ions floating around in the air.
	www.ccrane.com /library/sky-wave.04.22.02.aspx (675 words)

	Time and Frequency from A to Z
		In radio transmission, a wave that propagates close to the surface of the Earth.
		Groundwave propagation is a characteristic of low frequency (LF) radio signals.
		Since the propagation or path delay of a groundwave signal remains relatively constant, LF signals tend to be a better time and frequency reference than high frequency (HF) signals, which are often dominated by skywave.
	tf.nist.gov /general/enc-g.htm (587 words)

	[HCDX]: groundwave bandscan (NF)
		During the midday of Saturday (3 OCT), Neil and I drove down to a scenic seaside cliff area in Portugal Cove South, between Trepassey and Cape Race.
		The purpose of this trip was to obtain an accurate daytime groundwave bandscan from one of the most easterly sites in North America.
		Daytime Groundwave Bandscan - Portugal Cove South, Newfoundland Date = 3 OCT 1998 Receiver = Drake R8A Antennae = 200 m wire at 215 degrees and 100 m wire at 245 degrees
	www.hard-core-dx.com /archive/1998/msg02222.html (301 words)

	Hard-Core-DX.com: Groundwave Propagation On SW -- rule of thumb is 300 km on SW (Site not responding. Last check: 2007-10-20)
		Hard-Core-DX.com: Groundwave Propagation On SW -- rule of thumb is 300 km on SW Groundwave Propagation On SW -- rule of thumb is 300 km on SW Saturday, August 23 2003
		SW (using groundwave) is almost like AM / MW to a point, with dipoles.
		Subject: [HCDX] Groundwave Propagation On SW Groundwave propagation distance is definitely dependent upon transmitter
	archive.hard-core-dx.com /channels/hcdx/2003-08/20030823112118721.html (192 words)

	Groundwave Article, Groundwave Information (Site not responding. Last check: 2007-10-20)
		Lower frequencies, especially AM broadcasts in the mediumwave and longwave bands (and other types of radio even below that), travel most efficiently this way.
		At night, mediumwave and shortwave transmissions travel better by skywave.
		We take no responsibility for the content, accuracy and use of this article.
	www.anoca.org /earth/radio/groundwave.html (214 words)

	The Theory of Wireless Telegraphy -- Groundwave discussions (1904)
		It is interesting to note that at one point Stone stated that as radio signals spread out, their strength diminished with the square of their distance.
		This was actually an error, as groundwave radio signal strength actually tended to diminish directly with distance, as they spread across the earth in just two dimensions.
		With his extensive practical experience, DeForest noticed that Stone's statement was at variance with his work -- this would have been especially noticeable where the signals traveled over highly conductive paths, such as sea water.
	earlyradiohistory.us /1904gw.htm (874 words)

	VHF UHF BAND CHARACTERISTICS
		Generally shorter groundwave distances of around 200 miles can be expected on this band with a modest SSB or CW station.
		This band is not available in many countries other than the USA.
		Groundwave coverage is quite limited compared to 2 meters due to high absorption.
	www.hamuniverse.com /vhfuhfbands.html (347 words)

	Shortwave Propagation
		At the lower end of the shortwave spectrum, groundwave coverage is fairly good, on the order of a hundred miles with up to 1000 watts.
		As you go up in frequency, groundwave coverage decreases, so that at 27 mHz, where CB radio lives, it is only a few miles.
		However, it is not groundwave that people use these frequencies for.
	dzabcik.home.texas.net /propagation.html (670 words)

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