random length

Petlowany Antennas by K6NO - WorldRadio Article on Petlowany antennas base on this principle: if a length of wire is wound into a spiral-shaped coil and excited by a radio frequency current connected to the innermost portion of the coil, it will then, and only then, exhibit RF characteristics that closely approximate those of a resonant linear wire of the same length

Shortened dipole for 10 & 40m bands - A shorten Dual-Band Dipole with overall length of about 11 m. For this antenna traps are substituted by inductors, in order to cover the 10 & 40 m. Bands.

160 meter linear loaded Inverted L antenna - The total length of the inverted L is 240 feet, which is 7/16th of a wave length long. It has a 92 foot horizontal linear load section 1 foot above ground that terminates into a home-brewed parallel network tuner by KN4LF

Loaded dipole for 1,8 Mhz - Total Length: 26 m (85 ft.); Total Weight: 380 g;

Multi-Band Super Mini Loop Antenna  ^pop - How to make the Super antenna. To build this antenna you need a lot that is at least 100 feet across. Antenna covers all bands 80-10 meters + 30, 17, 12 meter WARC Bands This antenna works as a Full Wave Loop on 80 Meters and also works as a 2 wavelength open loop or Bi-Square on the 40 Meter band

Coaxial cable dipole for 80m - Here are some simple antennas you can build along with calculators to help you get the right length.

Antenna wire catenary calculator - This is a simple calculator for solving the antenna wire catenary between to end points given the design wind speed, mass per unit length of the wire, wire diameter and Gross Breaking Strength of the wire.

The Gain of an Endfire Array - This article looks at the maximum theoretically possible directive gain that could be obtained with an endfire array of given length or number of elements, and compares this with practical results in the literature.

Random wire Unun - Get all band coverage with a single wire and the icom 703

Build a Basic Beverage Antenna - Basically the Beverage is a travelling wave antenna made of a length of wire a small height (relative to the wavelength of interest) above earth. It can be terminated for unidirectional reception or left unterminated for bi-directional reception.

Choke coax length - Discussion about choke length

Coaxial antennas - G3TXQ study on coaxial cable demonstrate that it can reduce an element's length by something approaching the Velocity Factor of the cable

W5JGV Mobile Antenna - A High Efficiency Extended Length Mobile Antenna The antenna itself is 3.42 meters or 11 feet 2 inches long from the top of the mounting spring to the tip. By W5JGV

The KJ5VW 20 Meter Mini Yagi - 2 element mini-yagi that weight less then 15 pounds, cost less than $30 dollars, can be disassembled into four-foot lengths by Gary R. Hanson, KJ5VW

The Grid Yagi for 144 Mhz - The Grid Yagi (or Grid Quad) is a high performance yagi antenna that can be built with readily obtainable inexpensive materials. Described here is a 6 element 2 meter version with a boom length of about 1 wavelength, shown

Build a Tuned Loop - How can you vastly improve your Medium Wave reception? its quite simple really, all you need is 120 foot of wire, a few lengths of timber and an old tuning capacitor with which you can build the answer to every DX'ers prayers, a tuned loop antenna.

Random wire antenna for shortwave listening - VA3STL experience on reorganizing his shack and setting up a new random lenght wire antenna for his Yaesu FRG-7 receiver

UHF Yagi for AO-40 - Based on DL6UW Yagi antenna's design-formula The forward gain is 13.6 dBi (about 11.5 dBd) and it's pretty small, about 1,5 m in length

Earth Systems - In order to resonate at a particular frequency, an antenna needs to be at least one half wave length long. Antennas below a 1/2 wave are dependent on a ground system for resonance as well.

VHF 5/8wave vertical antennas - By Guy, de ON6MU, At VHF, both the 1/4-wavelength monopole and the 5/8-wavelength monopole antennas are widely used.

W3DZZ multiband dipole - The multi-band trapped dipole is resonant on approx 3.7, 7, 14, 24 7 28.5 Mhz. The overall top length needs to be approximately 32.9 Meters

The Zeppelin antenna - It consists of a radiating wire with a length equal to the half-wave of the fundamental frequency for which the antenna is cut.

Shortest Vanity Callsigns  ^updated - This is a service for finding the shortest available vanity callsign in your amateur radio class. It filter through all possible callsigns and provide just the unused ones weighted by their length in morse code or their actual number of letters.

Procedures for Digital EME - Recommended Procedures for Random Digital EME

Interdigital bandpass filter designer - Fill out the form to design a bandpass filter as described in the January 1985 issue of Ham Radio Magazine. These filters are generally limited to frequencies above 200 MHZ because their size is slightly longer than 1/4 wavelength