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	What is a magnetic loop antenna
		A magnetic loop antenna is so called because unlike a conventional wire dipole the small transmitting loop aims to generate the magnetic field rather than the electrical one.
		A magnetic loop antenna is comprised of a (usually but not necessarily) round conductor of a total length perhaps one quarter (Roberto I1ARZ Radio Communication March 1992 p66-68 and April 1992 p30-31) or more commonly for short wave one fifth or one eight of a wavelength.
		Such loops are simple to build, and are regularly a solution when a transmitting antenna for shortwave frequencies is needed indoors, in a very small garden, to be hidden, or where there is local electrical interference, or a high density of broadcast television receivers.
	www.geocities.com /gw0tqm/magloop/magwhat.htm (1029 words)

	Intermediate-sized loop antennas.
		Since the current is assumed constant around the loop circumference, the lengths of the phasors involved in this calculation are identical, and, were it not for the phase delay for the radiation to cross the diameter of the loop, the phasor contributions would be exactly opposite in direction, resulting in complete cancellation.
		Loop radiation is often (usually) measured with the loop mounted in a vertical plane, and one goes away a significant distance on a flat ground so that the radiation is measured on a horizontal (level) path in the plane of the loop.
		In the case of the 500mm circumference loop with an antiresonance at 171MHz, we may deduce that the inductance of the loop, regarded as a single turn of non-radiating wire, is tuned or balanced by the capacitance of a folded dipole mode, for a total dipole length of lambda/4.
	www.ee.surrey.ac.uk /Personal/D.Jefferies/loop.html (4546 words)

	[No title] (Site not responding. Last check: 2007-10-13)
		Various articles have appeared describing magnetic loops for HF use, some with complicated methods of remote tuning and the antenna can be quite a useful and interesting project.
		The inner of the SO239 socket at the base of the loop is soldered onto the centre of the loop, with the inner forming a gamma match to the tube, about 9 inches from the earthy connection.
		Maximum radiation is off the ends of the loop, not broadside on, as in a quad or delta loop.
	www.g3ycc.karoo.net /loop.htm (412 words)

	An Easy to Build Shielded Magnetic Loop Probe
		This is not as much of a problem for a round loop as it is for a square loop because of the relatively sharp corners of the square loop.
		Next, the end of the BNC connector and two ends of the loop are covered in copper tape which is soldered to the copper foil of the loop as illustrated in Figure 7.
		The loop's shielding may be tested as described in "Signal and Noise Measurement Techniques Using Magnetic Field Probes" by applying an electric field source to the loop.
	www.emcesd.com /tt120100.htm (790 words)

	Magnetic Field of a Current Loop
		Examining the direction of the magnetic field produced by a current-carrying segment of wire shows that all parts of the loop contribute magnetic field in the same direction inside the loop.
		Electric current in a circular loop creates a magnetic field which is more concentrated in the center of the loop than outside the loop.
		The application of the Biot-Savart law on the centerline of a current loop involves integrating the z-component.
	hyperphysics.phy-astr.gsu.edu /hbase/magnetic/curloo.html (220 words)

	Magnetic loop antenna new theory
		The loops shown are all coupled with a ferrite transformer which is used to match the 50 ohms coaxial feeder to the feedpoint resistance of the loop.
		The loop is then resonated with a variable capacitor usually situated in the same container as the transformer to make a tuning and loading unit which can be remotely controlled.
		Measuring the current around the loop to prove the above theory was achieved by cutting the loop at the three point indicated in the above drawings and inserting three thermocouple RF amp meters.
	members.aol.com /benprom/index.htm/theory.html (554 words)

	Magnetic Loop FAQ
		A Magnetic loop or STL (small transmitting loop) is a large coil with a capacitor added to bring the system to resonance.
		The loop is brought to resonance by attaching a capacitor to the two open ends of the loop.
		Magnetic Loops also radiate RF at all angles, so they are well suited for both high and low angle reception and transmission.
	www.standpipe.com /w2bri/faq.htm (1976 words)

	Single-Turn Transmitting Loop Antennas of Various Regular Shapes
		Magnetic loop antennas are so named because most of the energy in the near field is contained in the magnetic component and very little in the electric component.
		Because of the large RF current flowing in the loop and the small radiation resistance, to obtain a usable radiating efficiency the loop conductor is formed from self-supporting copper or aluminum tube, or a broad flat strip.
		Useable efficiency can be obtained when a loop's diameter is as small as 2 percent of a wavelength or less and so magloops are popular for their space-saving qualities, unobtrusiveness, with no need for a ground radial system.
	www.smeter.net /antennas/magloop4.php (755 words)

	Small Magnetic Receiving Loops
		Very close to a small loop antenna (but not necessarily near the open ends of the small loop where the tuning capacitor is) the magnetic field dominates.
		That means a magnetic loop is actually electric field dominant at a very modest distance in the near field area.
		The loop must also be symmetrical, each side must be excited equally, and you must mount the loop so the feedline and any metallic supports leave the center area of the loop with maximum symmetry.
	www.w8ji.com /magnetic_receiving_loops.htm (1933 words)

	Hysteresis Loop
		The loop is generated by measuring the magnetic flux of a ferromagnetic material while the magnetizing force is changed.
		As the magnetizing force is increased in the negative direction, the material will again become magnetically saturated but in the opposite direction (point "d").
		However, the level of residual magnetism may be lower than the retentivity value when the magnetizing force did not reach the saturation level.
	www.ndt-ed.org /EducationResources/CommunityCollege/MagParticle/Physics/HysteresisLoop.htm (625 words)

	VHF TX Loop
		The loop is circular with a diameter of 5.25 inches (133 mm) and made with 0.25 inch (6.4 mm) copper tube.
		To enable variable tuning of the loop, natural resonance formed by the loop inductance with its self capacitance must be at a frequency higher than the operating frequency.
		In a larger loop made for the HF bands, I used 0.75 inch (19mm) copper tube but I thought that this was a bit cumbersome for the small 2 metre loop and settled for the 0.25 inch tube.
	users.tpg.com.au /users/ldbutler/VHFLoopAntenna.htm (1947 words)

	MAGLoop Antenna / magnetic loop antenna (Site not responding. Last check: 2007-10-13)
		The magnetic loop antenna is an extremely efficient short wave antenna for the small size it constitutes.
		The diameter of the loop is in the range of 1/10 to 1/100 of the wavelength.
		The indicated length of half loop diameter is near to the optimal length.
	home.datacomm.ch /hb9abx/loop1-e.htm (1502 words)

	Portable HF Transmitting Loop Antenna
		While HF antennas are not normally known for their small size, magnetic loops can offer quite respectable performance, at the cost of some efficiency and extremely narrow bandwidth.
		Elecraft notes on magnetic loop antennas This is a very well done article with lots of pictures, good explanations, and great ideas for further experimenting.
		Magnetic Loop Antennas This page documents some truly beautiful and inspiring construction and offers sage advice borne of experience.
	dt.prohosting.com /hacks/antenna/magloop.html (2734 words)

	A Magnetic Loop Antenna for Shortwave Listening (SWL) by KR1ST
		A second loop, which is one fifth of the diameter of the large loop, is connected to the feedline and this small loop is positioned in the large loop on the opposite side of the tuning capacitor.
		When you look at the many designs of magnetic loops on the internet, or in various other publications, you’ll notice that there are different ways to construct coupling loops.
		The coupling loop needs to be mounted on the opposite side of the tuning capacitor, which is the bottom of the main loop.
	www.kr1st.com /swlloop.htm (3789 words)

	Magnetic Loop Antenna de AA8C
		The pickup loop is a single turn of #24 enameled wire wound about an inch inside of the main loop on holes in the central vertical and horizontal spars.
		Orienting the loop horizontal with respect to the earth will result in a null condition wherein all but the strongest signals are effectively cancelled out when the antenna is near the surface of the earth.
		This is a magnetic loop antenna, and materials that exhibit ferromagnetic behavior (particularly iron, steel, and nickel) will add to your noise figure and mess with your antennas' resonant frequency and radiation pattern in ways that are both wierd and magical.
	members.verizon.net /~vze24qhw/loop.html (2530 words)

	The Single Turn Magnetic Loop Antenna
		A horizontal loop is similar to a vertical radiator in that its propagation is omni-directional.
		The normal propagation for the loop was in the North/South direction, but his 15m transmission was East/West, off the sides of the loop, not through it.
		This is not to say that there is no interaction, since it is obvious that a low horizontal loop will certainly have some small capacitance between the antenna and ground, but it is negligible and has a minimal influence on the overall behavior of the antenna at the fundamental frequency.
	ka1fsb.home.att.net /loopants.html (4099 words)

	Developement of the G0CWT Magnetic loop (Site not responding. Last check: 2007-10-13)
		I first used this type of loop in 1985 but at that time it consisted of 64 foot of wire hung from a mast with a spreading cane near the top and was fed with R.F. using a single turn coupling coil at the top of the loop.
		Now the second requirement of my loop was that it could be tuned up on 160 metres so to do this I had to find the feed point impedance on this band,well to cut a long story short it turned out to be 2.
		So to make the loop suitable for both bands I had to make a transformer with a primary of 9 turns taped at three turns and a secondary of 2 turns and switch it remotely by relays from 3 to 9 turns to change from 80 to 160 metres.
	members.aol.com /benprom/index.htm/designe.html (676 words)

	Thinking about Ideal Loops
		Running the loop into the virtual ground at the summing node, the distributed capacitance of the loop has no effect on the output, since there is no voltage between adjacent turns.
		Well, the magnet is a DC signal, a steady magnetic field, and the disc is a shorted loop of zero resistance a current flows in the loop, perfectly mirroring the field of the magnet, which is reflected!
		In this design the loop has an intrinsic low impedance, and common mode voltages are ignored by the op-amp, so screening is really not necessary; also, stray capacitance is ignored, since there is no voltage difference between turns, so no current in the associated capacitance.
	www.vlf.it /looptheo7/looptheo7.htm (2690 words)

	PA3CQR Magnetic loop antenna homepage (Site not responding. Last check: 2007-10-13)
		The main loop is inductively coupled to the transceiver with a smaller loop.
		This coupling loop can be made in various ways but always has a diameter which is 5 times smaller than the main loop.
		The loop needs to be tuned carefully and the practical bandwidth varies from 20 kHz on 17m to 100 kHz on 10m.
	www.iri.tudelft.nl /~geurink/magnloop.htm (691 words)

	Build a Magnetic Field Immunity Tester - Test & Measurement World (Site not responding. Last check: 2007-10-13)
		A corresponding parameter for the induced magnetic field in an area perpendicular to the magnetic flux path.
		Verify that the effects of the magnetic field on the EUT are acceptable and that the equipment is able to recover by itself when you remove the field.
		Measure the field generated by the magnetic loop with either a Gaussmeter or a small calibration loop antenna.2 If you use the loop antenna, you must connect it to either an EMI meter or a spectrum analyzer.
	www.reed-electronics.com /tmworld/article/CA187497.html (1245 words)

	Magnetic Loop Antenna
		I was handed a leftover roll of 7/8" Cellflex cable from which I'm building a Magnetic Loop Antenna for 80 and 40 meters.
		The loop is made using the 7/8" Coax cable.
		The coupling loop is made from roughly 200 cm of 2.5 square mm ordinary installation wire.
	home.planet.nl /~niess153/magnetic_loop_antenna1.htm (247 words)

	My Magnetic Loop Antenna
		This loop covers a frequency range of about 5 MHz to 22 MHz and is built from readily available parts.
		A sound sample is included showing the dramatic difference between the magnetic loop and the built in whip on a portable shortwave receiver.
		The magnetic loop is small, reasonably efficient even close to the ground, has a low take off angle and it has a deep null on each side which lets you null out interference.
	www.kr1st.com /magloop.htm (622 words)

	Multi-band Backpacking Magnetic Loop Antenna - Ham Radio Project - Doug's Domain / WA0VSL (Site not responding. Last check: 2007-10-13)
		The main loop ends are then soldered to the main tuning capacitor stators, there is no connection to the rotor.
		The main loop is formed into a octagon with eight 1.5' long 1/8" diameter fiberglass spreader rods radiating from a center hub formed of brass ferrules (SteelWorks® brass round tube, 5/32" O.D.) soldered onto a small double-sided PC board octagon (1 3/8" face-to-face).
		There is a slight amount of tension created by the length of the loop (if not, shorten the loop before final tune-up via the fixed capacitor trim) versus the radius, plus the 'springyness' of the loop which firms up the loop assembly and keeps it in place.
	home.earthlink.net /~wa0vsl/BPmag-loop.html (2372 words)

	Magnetic Loop RF & You
		Before firing up his new magnetic loop, he wondered if it was safe to TX on HF using 100W with the Loop within a 10-12 foot proximity.
		The magnetic loop antenna is believed by many to have some advantages over others especially as to its more compact size and lack of need for a good ground.
		Since most loops have taken a square form, the question is usually asked in terms of the adjustment needed, if any, to transform the loop into a circle and still be resonant.
	www.antennex.com /Stones/st1103/maglooprf.htm (2742 words)

	Magnetic Loop Antennas, Magnetic Loop Info, How to Build A Magnetic Loop, W2BRI Loops
		Magnetic Loops should not be confused with full size resonant loops commonly found in many radio operators backyards.
		The Magnetic Loop is a complex antenna and will not simply work as a plug and play solution.
		If you wish to build a Magnetic Loop antenna and have questions about how to make it work, this section is for you.
	www.standpipe.com /w2bri (698 words)

	Yohkoh Flare Images
		Its presence there indicates that the magnetic field structure must not be just a simple loop.
		The diagram suggests that the electrons are not accelerated in the soft x-ray loop, but in the cusp above the loop.
		This magnetic field configuration provides a location above the soft x-ray loop for the hard x-ray source, but it does not explain why it is located there.
	hesperia.gsfc.nasa.gov /sftheory/flareimage.htm (523 words)

	Grand Unified Theory: Wave Theory - Phase Transition Equation
		Under ideal conditions, such as the photon, the two loops are equal insofar as the properties of their energetic matter are concerned.
		The phase transition of a photon is in a state of duality whereby the magnetic loop equals the energetic loop, which equals 1.
		In this phase, the magnetic loop is induced to compliment the energetic loop by accelerating the pace at which it spins.
	www.grandunifiedtheory.org.il /eqPT1.htm (304 words)

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