coil

141 links - and 1 categories

20m Coil-Shortened Dipole - Build a low-cost 20m shower rod dipole antenna
[ Hits: 104 | Votes: 0 | Rating: 0 ]

The Vertical Buddi Beam for 20m - The Vertical Buddi Beam on 20m using no Coils. n this article I am going to describe a totally new way to construct and use a very old design the two element Yagi antenna. Unlike the traditional Yagi this design does not require a Tower or a boom, it is 100 percent portable and most important high- performance and easy to assemble using standard Buddipole components.
[ Hits: 579 | Votes: 2 | Rating: 4.5 ]

Make a Compatct Dipole for 7 MHz - This article demonstrate how to build and mount a 40 meter loaded dipole using basic materials. This antenna reduce the overall length of an HF dipole through the use of loading coils.
[ Hits: 216 | Votes: 0 | Rating: 0 ]

Coil-Shortened Vertical Antenna Calculator - You can shorten a vertical antenna by using a loading coil. This online calculator tells you how the amout of inductance your loading coil will need to have.
[ Hits: 312 | Votes: 2 | Rating: 5.5 ]
Antenna too short! Inductivity matching with coil match. - Wire antenna calculator with inductivity matching coil where length shorter lambda/4
[ Hits: 132 | Votes: 0 | Rating: 0 ]

Microvert Antenna for 40m by ON7IR - A mircovert antenna assembled for the 40m version of the DL7PE antenna. A one meter long aluminum tube with 24mm diameter is used for the base (element 1) and a 50cm aluminum tube with 20mm diameter for element 2 (the extention). A pvc pipe, 34cm long and with a diameter of 38mm, is used to wind the coil on (1mm enamelled copper wire).
[ Hits: 152 | Votes: 0 | Rating: 0 ]

An introduction to the air cored coil - We use the term air core coil to describe an inductor that does not depend upon a ferromagnetic material to achieve its specified inductance. This covers the cases where there really is just air inside as well as windings upon a different insulator such as bakelite, glass or PTFE etc. Do you need an air coil?
[ Hits: 106 | Votes: 1 | Rating: 2 ]

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: 350 | Votes: 3 | Rating: 8.67 ]

8010 Enfed Antenna - With this antenna the coverage is 80,40,20,15 and 10 meter band without any antenna tuner and the average SWR is below 1.2 on phone bands. The total antenna lenght is about 23 meters , with one 20.4 meters long segment from the 1:49 transformer to the 110uh coil and about 2.2 meters long segment from the coil to the insulator.
[ Hits: 142 | Votes: 0 | Rating: 0 ]

End-Fed Half-Wave Antenna for 20m 40m 80m - How to Design and Build a Field Expedient End-Fed Half-Wave Antenna for 20m, 40m and 80m. This Shorty 80m EFHW comprises a 49:1 autotransformer (to match the very high impedance at the end of a half-wave wire), a half-wavelength wire for 40m (also a quarter-wavelength for 80m), a loading coil and a short tail wire. The coil and the short tail wire (about 6 feet) make up the other quarter wave on 80m.
[ Hits: 141 | Votes: 1 | Rating: 4 ]
40m QRO End Fed Half Wave Antenna Coupler - A medium power End Fed Half Wave Antenna coupler, specifically tuned to the QRP frequency of 7030 kHz. Constructed from coil stock and capacitors, it achieves an impedance ratio of 64:1. The coupler has proven effective for power ranges from 2 to 100 Watts on the 40m band.
[ Hits: 104 | Votes: 0 | Rating: 0 ]

How to find out if your choke works - How many times have you heard the advice to coil a few turns of coax at the antenna end to form a choke. How to find out if your common mode current choke really works
[ Hits: 211 | Votes: 1 | Rating: 9 ]

DIY Portable Car Whip Antenna - Being frequently away from home, the author owner of an Elecraft KX3 missed the opportunity to work /M. They devised a portable antenna solution, incorporating a coil and car body, enabling multi-band tuning. Despite its unconventional design, the antenna exhibits promising performance, resembling a vertical dipole.
[ Hits: 54 | Votes: 0 | Rating: 0 ]

Short Multiband Dipole Array - A multiband shortened fan dipole. This page offers and online calculator that can be really useful if you plan to homebrew a multiband dipole for low HF bands and you don't have all needed space for the full lenght. It combines multiband dipole with loading coild for selected bands.
[ Hits: 229 | Votes: 0 | Rating: 0 ]

Cushcraft R7000 Prob/Repair - Repairing a Cushcraft R7000 antenna featuring several problems, mostly concerning coils and the insulating parts of the antenna.
[ Hits: 209 | Votes: 1 | Rating: 10 ]

Z Match with Toroid - A single coil Z-Match. This QRP version by G3WQW, using a T130-2 toroidal inductor and polyvaricon variable capacitors was published in Sprat 84.
[ Hits: 100 | Votes: 0 | Rating: 0 ]

The Squid Pole Wire Antenna Re-visited - The author explores enhancing the performance of a 7-meter fiberglass squid pole wire antenna for amateur radio. The wire, resonant at 10MHz, poses impedance challenges on various bands. Experimenting with direct coax feed and UN-UN transformers, the LDG Z11-Pro2 auto-tuner is found effective but may show deceptive SWR readings. The author employs adjustable UN-UN ratios and introduces a custom "porcupine" coil to optimize the antenna's efficiency.
[ Hits: 91 | Votes: 0 | Rating: 0 ]

Wolf River Coil - Vertical Base Replacement Coil. Wolf River Coil build quality antenna coils that are easy to tune and easy to install.
[ Hits: 167 | Votes: 0 | Rating: 0 ]

The FT-817 Calibration Menu - One of the interesting features of the FT-817 is that many of the conventional calibration settings that would have, in the past, been done using manual adjustments of coils, capacitors, and potentiometers, are done via software.
[ Hits: 128 | Votes: 0 | Rating: 0 ]

BITX QRP RTX - An easy to build 6 watts SSB transceiver for 14MHz. BITX is an easily assembled transceiver for the beginner with very clean performance. Using ordinary electronic components and improvising where specific components like toroids are not available, It has a minimum number of coils to be wound.
[ Hits: 103 | Votes: 0 | Rating: 0 ]