wi fi antenna

558 links - and 1 categories

Coax Dipole for 2 meters band - A homebrew 2m 144.2 MHz vertical 1/2 wave Coaxial Dipole antenna project for your home QTH, SOTA, portable field operations/WICEN exercises or the emergency 2m Go-box. Elsewhere in amateur radio circles this antenna is known as a 2m Flower Pot Antenna
[ Hits: 250 | Votes: 3 | Rating: 6 ]

An 80 m dipole antenna for restricted spaces - You can bend the wires in a half-wave dipole so that it takes up less space, with minimal loss of efficiency.It is advisable to get the ends of the antenna as high as possible, especially if children and animals are kept in the area around the antenna, as there are very high tensions on the ends of the antenna during transmission! In Norwegian
[ Hits: 186 | Votes: 0 | Rating: 0 ]

Double BiQuad Antenna Calculator - Online antenna calculator for homemade double biquad antenna for UMTS 3G 4G WiMAX WiFi frequencies. Article includes also a simple biquad antenna for 4g
[ Hits: 159 | Votes: 2 | Rating: 5.5 ]

20 / 40 Meter Short Coil Loaded Dipole Antenna - Experimenting a 20 40 meter short coil loaded dipole antenna with the goal to keep the total length under 40 feet so that the dipole can be mounted on two 20 foot fiberglass pole to make a 20/40 meter rotatable dipole.
[ Hits: 352 | Votes: 3 | Rating: 8.67 ]

Testing End Fed Long Wire Antenna - Testing a 27.2 metre end fed long wire antenna,used for SOTA activations placed as an inverted V. The author reports in this article an on the field practical result.
[ Hits: 168 | Votes: 0 | Rating: 0 ]

The Quarter-wave stub - The Quarter-wave stub can be used for many purposes. If it is left with an open end it can be used as a notch filter to attenuate certain frequencies. A quarter wave length of a transmission line can also be used as an impedance transformer, to know more about the Quarter-wave impedance transformer
[ Hits: 136 | Votes: 1 | Rating: 8 ]

Helical Antennas for 144 MHz - This article is about two excellent small helical antennas for the two meters band. With performance close to that of full sized antennas, these small helical antennas are low in profile but high in efficiency.
[ Hits: 230 | Votes: 1 | Rating: 7 ]

What is Horn Antenna - Horn Antenna - The energy of the beam when slowly transform into radiation, the losses are reduced and the focussing of the beam improves. A Horn antenna may be considered as a flared out wave guide, by which the directivity is improved and the diffraction is reduced. One of the first horn antennas was constructed in 1897 by Bengali-Indian radio researcher Jagadish Chandra Bose in his pioneering experiments with microwaves. The modern horn antenna was invented independently in 1938 by Wilmer Barrow and G. C. Southworth. This Horn model antenna is suitable employed in the UHF or SHF radio bands. Making this horn model antenna it will be easy for a beginner to make if it works in the 10GHz frequency, because small dimensions so it is not so difficult and also offers gain up to 25dBi.
[ Hits: 74 | Votes: 0 | Rating: 0 ]

Small Loop Antenna for the 80m to 10m - This article describes the development of two tunable antennas each consisting of three interconnected small loops and capable of providing excellent DX performance. The aerials are home-constructed, and located in a very small garden with a minimum of visual impact on the neighbours and are low enough in height to avoid the attention of UK planning authorities.
[ Hits: 405 | Votes: 1 | Rating: 8 ]

A More Efficient Magnetic Loop Antenna - The idea behind this antenna was to use multiple conductors in parallel to reduce the resistance losses in the antenna , and thereby improve the efficiency.For a given magnetic loop antenna, doubling the number of conductors from one to two will typically increase efficiency by about a factor of two. There is a limit, and beyond three or four conductors further increases are small, and may not be worth the bother.
[ Hits: 215 | Votes: 2 | Rating: 5.5 ]

Short Antenna for 40-30-20 Meters Band - This page describes an entirely simple, One-Knob matchbox that will match this antenna efficiently on 40, 30 and 20m, using a simple circuit that can be switched between series-resonant and parallel-resonant with just one banana jumper
[ Hits: 238 | Votes: 1 | Rating: 7 ]

The M0CVO HW-42HP OCF Antenna - A multi-band off centre fed dipole, designed to operate on all bands from 40m (7MHz) to 6m (50MHz). Author claims it will operate on 40, 30, 20, 17, 15, 12 and 10m without an ATU (SWR <3:1) plus 6m with an ATU.
[ Hits: 274 | Votes: 0 | Rating: 0 ]

How does an antenna tuner work ? - Collection of several topics on antenna tuners and their performance. Why use an antenna tuner? How does an antenna tuner…tune Does an antenna tuner fool the radio? Will an antenna tuner waste power? Can an antenna tuner help get more power to the antenna?
[ Hits: 185 | Votes: 0 | Rating: 0 ]

80m-40m Dual-Band Vertical - A dual band 40-80 vertical antenna on an 18m Spiderbeam Fiberglass Spiderpole, with monoband performance
[ Hits: 160 | Votes: 2 | Rating: 10 ]

Field Day Inverted L - Inverted L antenna, even if not completely freestanding, it only requires one line to be lauched into a tree to support the end of the horizontal wire. This project is done with a 31-foot Jackite pole for a support and uses six 15-foot radials and one 33-foot radial.
[ Hits: 88 | Votes: 0 | Rating: 0 ]
Random Wire Antenna Lengths - When on the trail, at Field Day, or whenever a good antenna is unavailable, a random wire can save the day, but it is important to understand its properties.
[ Hits: 186 | Votes: 1 | Rating: 2 ]

I5HGM KiwiSDR - A software defined receiver located in Tuscany Italy with a Windom antenna convering HF bands
[ Hits: 172 | Votes: 2 | Rating: 10 ]

Elecraft K2 Preselector Modification - Although most Preselectors are designed with an internal T/R relay, theoretically enabling direct insertion between the transceiver and the antenna, there is a problem when running CW, especially when running full QSK. The switching time of the internal relay is too slow to follow full QSK. The best way to avoid this problem altogether is to insert the Preselector directly into the transceiver’s RX antenna line, thus avoiding entirely the need to switch the Preselector in and out.
[ Hits: 189 | Votes: 0 | Rating: 0 ]

Automatic Arduino Antenna Switch - A Programming-Free Automatic Arduino Antenna Switch project published on NCJ
[ Hits: 452 | Votes: 0 | Rating: 0 ]

RF Exposure Calculator - To use the RF Exposure Calculator, fill-in the form with your operating power, antenna gain, and the operating frequency. Depending on how far above ground the RF source is located, you might want to consider ground reflections too.
[ Hits: 102 | Votes: 0 | Rating: 0 ]