what are quadrifilar helix antenna?
482111
A helical antenna is an antenna consisting of one or more conducting wires wound in the form of a helix. A helical antenna made of one helical wire, the most common type, is called monofilar, while antennas with two or four wires in a helix are called bifilar, or quadrifilar, respectively.
871590
Major and minor grooves. The strand backbones are closer together on one side of the helix than on the other. The major groove occurs where the backbones are far apart, the minor groove occurs where they are close together. The grooves twist around the molecule on opposite sides.
1468762
A Yagi–Uda antenna, commonly known as a Yagi antenna, is a directional antenna consisting of multiple parallel elements in a line, usually half-wave dipoles made of metal rods. ... The reflector element is slightly longer than the driven dipole, whereas the directors are a little shorter.
587318
Single quadrupole systems contain only one mass filtering quadrupole while triple quadrupole systems consist of three quadrupoles. Q1 and Q3 are working as mass filters while Q2 is acting as collision cell. Quadrupoles can be used in scanning or filtering mode.
503042
The coil or search head of these detectors consists of two separate coils of wire. The outer coil produces a VLF, below 30kHz, impulse which is directed into the ground. When the impulse comes into contact with a metal object below ground, the impulse is reflected back at a different frequency.
443540
In the Figure, Given Below, Abcd is a Cyclic Quadrilateral in Which ∠Bad = 75°; ∠Abd = 58° and ∠Adc = 77°. Find: (I) ∠Bdc, (Ii) ∠Bcd, (Iii) ∠Bca.
1450296
To answer the original question very simply, no, SWR can't be too low. It can be too high. And, an swr of something around 1.5:1 isn't a problem especially with the average 102" whip (in fact, it's pretty good). It's not uncommon for an antenna to ~not~ be a 50 ohm load.
330668
There are two main types of secondary structures. Two fibrous structures the alpha helix, and the beta pleated sheet, which are structural components of the cell. The alpha helix is formed when the polypeptide chains twist into a spiral. This allows all amino acids in the chain to form hydrogen bonds with each other.
192353
Typically a cell tower is located at the edge of one or more cells and covers multiple cells using directional antennas. ... The type of antenna used for cellular base stations (vertical white rectangles in pictures), called a sector antenna, usually consists of a vertical collinear array of dipoles.
696923
Dipole Antennas Include: One area in which dipole antennas are often used is for the reception of VHF FM broadcasts. Many Hi-Fi tuners and other radios have input sockets that will accept the input from a coaxial feeder, and where no external antenna is used, a dipole antenna can provide an excellent solution.
363197
['Lobe piercings: standard lob piercing, transverse lobe piercing.', 'Outer ear piercings: tragus piercing, snug piercing, forward helix piercing, industrial piercing, auricle piercing.']
514552
['quadrant.', 'quadriga.', 'quadroon.', 'quadrate.', 'quadplex.', 'quadding.', 'quadrans.', 'quadrats.']
552316
The double helix of DNA is, like its name implies, in the shape of a helix which is essentially a three dimensional spiral. The double comes from the fact that the helix is made of two long strands of DNA that are intertwined—sort of like a twisted ladder.
874524
The double-helix shape allows for DNA replication and protein synthesis to occur. In these processes, the twisted DNA unwinds and opens to allow a copy of the DNA to be made. ... As the new strands form, bases are paired together until two double-helix DNA molecules are formed from a single double-helix DNA molecule.
1101123
As nouns the difference between antenna and antennule is that antenna is a feeler organ on the head of an insect, crab, or other animal while antennule is (zoology) a small antenna.
1184009
Excellent Multi-Use Antenna As all cord cutters like me know, it is very important to have a good quality antenna if you want live local programming. I have used multiple antennas through the years and I can say this ANTOP antenna is the real deal. PROS: - Does exactly what you want an antenna to do, gets local.
593254
Each specific antenna has a gain rating or dBi (decibel isotropic) number which coincides with the performance. The higher the dBi rating the larger the area the signal covers. Keeping that in mind and thinking about what your specific needs are you can begin to narrow down what antenna is best for you.