feed dipole

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Spiral Dipole Antenna for 40m - This antenna is an off-center fed spiral dipole for 40 meters. The spiral dipole is very compact, making it well-suited for limited space (like an apartment patio), while the off-center feed gives the antenna some multiband capability.
[ Hits: 295 | Votes: 3 | Rating: 7 ]

Linear Loaded 40m Dipole - Dipole for 40m band. It is a simple linear loaded dipole feeded with 450-Ohm openwire feedline. Designed it for resonance at 7.050 MHz, can be tuned on 30m and 80m bands with an external antenna tuner. Build with simple electrical copper wire (2.5 mmq/13 awg) and two fishing poles with size of about 7 m/23 ft.
[ Hits: 162 | Votes: 0 | Rating: 0 ]
40m loaded dipole - This is an short dipole for 7 MHz. Total length of this dipole is just 10 meters, 33 feet. Missing lenght is balanced by a coil made of 49 turns of a 40mm diameter pvc pipe. The use of a choke balun is recommended, as always, to adapt the unbalanced coax cable to the balanced antenna, and to prevent RF feed back along the coax shield.
[ Hits: 194 | Votes: 4 | Rating: 8.75 ]

Extended Double Zepp NVIS Antenna Calculator - Extended Double Zepp measurements for all ham bands, and online calculator. The antenna is constructed much like an ordinary Dipole antenna but with 5/8 Wavelength Elements matched with an added Impedance Matching Section of balanced feed line
[ Hits: 124 | Votes: 3 | Rating: 7 ]

Build your own HF balun - A balun is a MUST for dipoles or similar antennas when they are feed with coaxial cable. From the RF point of view, the shield can be modeled as two conductors, the internal shield (the real shield, this is, ground) and the external shield, who is really far to be ground. In this way, your dipole has 3 arms, the two from the dipole and the coaxial cable shield (external face)
[ Hits: 248 | Votes: 1 | Rating: 10 ]
How to Blow Up Your Balun - In this article, author examine stresses placed on common-mode chokes (aka baluns) as hams use/abuse them, examine the efficiency of simple dipole multi- band antennas and their feed systems. Stressing a Balun.
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80m-40m Loaded Dipole - A dual band dipole antenna for 40 and 80 meters band. Total lenght of 26 meters, foreseen two coils at aprox 11 meters distance from center feed.
[ Hits: 254 | Votes: 4 | Rating: 5 ]
The Story of the Broadband Dipole - A dipole can be broadbanded by a number of techniques including by matching with resonant sections of transmission feed lines.
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Quad Loop Antenna for 50 MHz - Building A Full-Wave Quad Loop Antenna for 6 Meters. This is an easy antenna to build and the materials cost about $15-20. It exhibits 1.8dB gain over a 1/2-wave dipole. Using an open-wire parallel feedline (commonly called ladder line) with an antenna tuner, it tunes up on the 10m band as a 5/8-wave loop as well
[ Hits: 199 | Votes: 1 | Rating: 1 ]

Moxon Mania - Building the Ultimate 4-Band Moxon Antenna - The article details the design and construction of a four-band Moxon beam by a radio amateur. The beam, mounted atop a rooftop tower, aimed for gain over a dipole on 20 meters, cost under $500, and included additional bands. The design features fiberglass spreaders, four bands (20/15/10/6 meters), and a single feedpoint. The construction involved computer modeling, NEC source code, and specific dimensions. The article outlines the assembly, materials, and tuning process, including in-situ adjustments for optimal performance. Despite initial challenges, the beam improved signal strength and facilitated contacts on multiple bands, marking it as the best HF antenna the author has owned.
[ Hits: 96 | Votes: 0 | Rating: 0 ]

Homebrew an OCF Off-Center Fed Dipole Antenna - This type of antenna is a popular antenna design as the performance is very good across the HF bands and requires little or no tuning. It’s a dipole fed off center with a 4:1 balun at the offset feed point. The antenna shown covers 80, 40, 20 and 10 meters. The formula can also be used to adjust the overall length to cover more or fewer bands and the resulting overall length. 160-10m, 80-10m or 40-10 meters depending on your available space. Other bands will require a tuner.
[ Hits: 198 | Votes: 3 | Rating: 6.67 ]
Tuning OCF L-Dipoles - The behavior of a straight dipole and its L-form is examined in terms of impedance and SWR. By adjusting the feed point or bending angle, impedance variation is observed. Impedance shifts symmetrically as the feed point deviates, leading to recommendations for optimal ratios. Model simulations aid in understanding and fine-tuning, crucial for achieving a 50 Ohm match. Practical tuning guidelines ensure efficient antenna performance.
[ Hits: 29 | Votes: 0 | Rating: 0 ]

T2FD Antenna - Terminated and twisted folded dipole - T2FD is a 600-900 ohms folded dipole, terminated with resistor. Feed impedance is coupled with 50/600 ohms voltage balun. It is a wide band antenna with rather low SWR over the full designed frequency range: antenna tuner is seldom needed.
[ Hits: 488 | Votes: 0 | Rating: 0 ]

Folded Dipoles in Yagi Uda Antennas - A folded dipole is an antenna, with two conductors connected on both sides, and folded to form a cylindrical closed shape, to which feed is given at the center.
[ Hits: 314 | Votes: 2 | Rating: 4.5 ]