rf meter

170 links

5 element Yagi antenna for 10 meters band - This 10 meter antenna is right out of the ARRL Antenna Book. There are 5 elements on a 24 feet boom and it performs well from 28.0 to 28.9 MHz.
[ Hits: 194 | Votes: 2 | Rating: 6 ]
Two on 10 - A two element beam antenna for ten meters band. This home-brew two-element beam is the perfect introduction to rolling your own gain antenna
[ Hits: 338 | Votes: 2 | Rating: 8 ]

160m 80m Vertical Antenna - A dual band vertical antenna for 160 and 80 meters band, on a 18m spiderbeam fiberglass pole. This vertical is a good compromise when you want good performance on these two low ham bands and don't have the space to install two seperate antennas.
[ Hits: 186 | Votes: 0 | Rating: 0 ]

A Simple High-Performance Vertical Antenna - This article describes the details of the design, which can be easily scaled for just about any HF band. The antenna described in this article is for the 20 meters band.
[ Hits: 666 | Votes: 3 | Rating: 9.67 ]

SAFARI 40-30m vertical Antenna - Roach pole vertical antenna for 40 and 30 meters band featuring good performance on short skips contacts compared to wire dipole
[ Hits: 310 | 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 ]

A very efficient half size 40 meter Vertical Antenna - A vertical antenna project for the 7MHz made with some spare parts. Based on a broken 20 foot fishing pole, it is based on a good ground system made with radials and a capacitive hat done to increase the global radiation resistance of the antenna. A custom loading coil is also included in this project to perfectly tune the antenna to the CW portion of the 40 meters band.
[ Hits: 736 | Votes: 4 | Rating: 8.5 ]

Half-Size 6 meter J-antenna - How to use a little known J-antenna characteristic to reduce a conventional 14 foot antenna to 7 feet. Perfect 50 Ohm match, same gain, no radials.
[ Hits: 63 | Votes: 0 | Rating: 0 ]

Choking balun for 160-30 meter band - Choking balun for lower HF and MF bands. (1.8MHz - 10MHz). Requiring a choking balun to isolate the potential RF pick up on the coax cable as it runs past equipment such as computer within the radio room at lower HF and MF frequencies a simple method of winding RG58 coax onto a Powdered Iron Toroid Core was constructed.
[ Hits: 196 | Votes: 3 | Rating: 6 ]

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 ]

Portable NVIS Loop for 80m to 40m - A portable (15.5 foot diameter) NVIS loop for 3.5 to 7.3 MHz. Performs well at high and low takeoff angles, and has smaller footprint than most NVIS antennas.
[ Hits: 366 | 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 ]

160 Meters 4 Square Receive Antenna - A four square array receiving antena for the top band, performance is extremely directional and space requirements are really hard to fulfill.
[ Hits: 181 | Votes: 1 | Rating: 10 ]

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 ]

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 ]

HF9V Antenna Setup and mods - Installation and modification of the popular Butternut HF9V antenna with the optional 160 meter addon. Article includes a modification to improve the performance on the top band
[ Hits: 196 | Votes: 2 | Rating: 10 ]

HyGain TH3JR Improvements - An analysis and performance improvement of the HyGain TH3JR on the 20 meters band.
[ Hits: 159 | Votes: 0 | Rating: 0 ]

RF Inductor Calculator - This air-core solenoid style RF inductor calculator calculates the inductance, wire size, number of turns, and other parameters for an air-core solenoid inductor used in radio frequency (RF) circuits, based on user input of frequency, desired inductance value, and physical dimensions.
[ Hits: 100 | Votes: 3 | Rating: 7 ]

RF Toroid Calculator - This RF Toroid Calculator provides graphical calculator used to determine the inductance and other parameters of ferrite and powdered-iron toroids. It simplifies the process of selecting the appropriate toroid for use in radio frequency (RF) circuits
[ Hits: 102 | Votes: 2 | Rating: 10 ]

SWR-Display - The intention was to determine also very small SWR ratios with small power exactly. With this SWR meter, for example, the inputs of RF amplifiers with power <-20 dBm can be measured. In German
[ Hits: 146 | Votes: 1 | Rating: 8 ]