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195 links - and 1 categories

Experiments with 160m antennas - Experimentin wire antennas on top band using several type of aerials. This includes a 40 to 160 meters EndFed Half Wave kite antennas and 160m/80m loaded vertical antenna.
[ Hits: 177 | Votes: 0 | Rating: 0 ]

30m Half -Size Rotary Dipole - A rotary dipole antenna for 30 meters band. Each arm is about 12.5 ft and is constructed from telescoping fibreglass flag/fishing poles and short lengths of aluminium tubing. Two short lengths of glass-fibre rod were used to insulate the arms from the supporting hardware.
[ Hits: 198 | Votes: 0 | Rating: 0 ]

Half-Length Dipoles for 40 Meters - Complete collection of the four main parts of this excellet research on modelling and designing half wave dipole antennas for 40 meters band, covering all aspects beginning from full wave length antennas, to shortened, loaded and reshaped dipoles
[ Hits: 383 | Votes: 2 | Rating: 10 ]

End-fed 6-meter Zepp - A half-wave antenna can be end-fed or center-fed. An end-fed half-wave antenna may offer mechanical and construction advantages over a center-fed antenna. The radiation pattern for an end-fed half-wave antenna is no different than a center-fed half-wave antenna.
[ Hits: 174 | Votes: 2 | Rating: 9 ]

J-Pole antenna for UHF Bands - This is a simple half wave antenna for 70 cm band, made using the jpole design.
[ Hits: 196 | Votes: 1 | Rating: 10 ]

80m Shortened Dipole Antenna - This antenna just requires about 24m of free space instead of 41m that a normal half wave 80m antenna needs to hang up. The so called loaded dipole uses a coil in every dipole arm to electrically lengthen the mechanical too short dipole arms. Every coil has an inductivity of 120 microHenry.
[ Hits: 154 | Votes: 0 | Rating: 0 ]
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 ]

Loading of Short Antennas - An interesting article on loading short vertical monopole antennas, representing six different methods. Base loading, Center Loading, Top Loading, Continuous loading, half and half loading and capacitive top loading.
[ Hits: 684 | Votes: 4 | Rating: 6.25 ]

Speaker Wire EFHW Antennas 20m/ 40m - Author experiments end fed half wave antennas using common two conductore speaker wire, this article features a couple of end-fed halfwave wires for the 40M and 20M bands.
[ Hits: 262 | Votes: 1 | Rating: 9 ]
Trapped five band EFHW SOTA antenna - A trapped multi band end-fed-half-wave antenna for 40/30/20/17/15m.
[ Hits: 424 | Votes: 1 | Rating: 10 ]
A simple NonDirectional Antenna for 10 meter - This article is about a simple vertical end-fed-half-wave wire antenna for 10 meters that can be used in case of restricted space.
[ Hits: 702 | Votes: 2 | Rating: 7 ]
1:49 unun for end fed half wave antennas - 1:49 UNUN using two stacked FT240-43 cores for end fed halfwave antenna. To match the end fed half wave antenna to the coaxial feeder, it is necessary to have a matching network or transmission line transformer.
[ Hits: 398 | Votes: 10 | Rating: 8.1 ]
End fed half wave antenna 40/30/20m - For my SOTA activities, i recently bought a QRP transceiver QRP SW-3B, which is a three-band QRP CW only for 40/30/20 m. So, i needed an antenna that would allow to use these 3 bands in SOTA portable activity. Already having some experience with the EFHW antenna, i decided to build one for 40/30/20m.
[ Hits: 168 | Votes: 0 | Rating: 0 ]

Improving Gain of the Super J-Pole Antenna - The collinear J-Pole, often known as the Super-J, does improve the behavior over a regular J-Pole. there is an advantage when vertically combining 1/2 radiating sections to have a bit of separation between the half-wave end points. Get 0.8 dB more gain out of the trusty Super-J by replacing the traditional phasing stub with a long coil.
[ Hits: 192 | Votes: 0 | Rating: 0 ]

2m Lightweight Portable Dipole - Lightweight portable QRP 2m & 70cm half wave dipole for SOTA or an emergency antenna for the 2m and 70cm Go-box.
[ Hits: 176 | Votes: 1 | Rating: 9 ]
Portable VHF UHF Dipole Antenna - A SOTA Lightweight Portable 2m 70cm Dipole Antenna Lightweight portable QRP 2m and 70cm half wave dipole for SOTA or an emergency antenna for the 2m and 70cm Go-box.
[ Hits: 177 | Votes: 0 | Rating: 0 ]
The GAWANT Antenna - The GAWANT Antenna, or Shinagawa Antenna is an half-wave vertical end-fed in a FT817-friendly package
[ Hits: 137 | Votes: 0 | Rating: 0 ]

Which part of a dipole radiates most? - The title may seem a strange question. Still, it is often said that the part where the current is largest, radiates most. And from that a rule of thumb follows, saying that if you don't have enough space to hang a complete half-wave wire dipole then try to make the central part hang as freely as possible.
[ Hits: 157 | Votes: 1 | Rating: 9 ]
The Weird Antenna Wire End Effect - A half wave wire that is tuned for resonance on 80m will NOT be resonant on 40m despite a precise harmonic relationship between the two bands. The End Effect is caused by a capacitive coupling between an unterminated wire end and the ground.
[ Hits: 95 | Votes: 0 | Rating: 0 ]

W3DZZ Multiband Antenna - An easy to build and extremely high performance antenna, works perfectly on all HF bands 3.5-28 MHz with some compromises, it is basically an half wave dipole for 40-80 meters, an LC circuit or trap 40 meters allows you to use a single radiating element.
[ Hits: 464 | Votes: 3 | Rating: 7.67 ]