A yagi antenna is 1/2 wave length per element. A one element 1/2 wave dipole is the same as the driven element of a yagi antenna. With some small size changes. Every element of a Cubical Quad antenna is a full wavelength long. More antenna material means more 'capture area' is in the air. And no degradation of performance at 2 meters and 70cm? Review of the Literature J. Harris - Stack tri band J-pole QST 1980 Suffers the same problem of 2 mt section radiating at UHF. Comet CX-333 $162 uses 3 radials (uses traps) Diamond –X3200A $164 uses 3 radials (uses traps) D. Mariotti –Heavy Duty Multi Band Vertical Antenna –CQ. Finished the antenna today with the updated dimensions and I am resonant at 152.4 mhz. Checking the 2 meter portion gives me a SWR of 4.2 It was a fun build, but just curious how your guys' cube came out. Dave Dec 28th 2018, 19:56: AD6ZH Joined: Jul 16th 2001, 00:00 Total Topics: 0 Total Posts: 0.
One of the most fun activitiesin Ham radio is learning to build your own equipment. In the early years ofamateur radio, long before factory-built equipment was easily available, Hamsbuilt their own radios and accessories. Why not continue the tradition? Hereare several projects you can easily complete in a few hours or less.
It’s likely your first Ham radiopurchase was a 2 meter or dual-band HT. Unfortunately, the rubber duck antennathat came with it isn’t the best choice for maximum signal. If you’re tired of peopletelling you your signal is weak, the simplest remedy is an improved antenna.
You’d be surprised how well this simple vertical antenna works, and it can be built with basic materials: wire and coaxial cable. You can tape it up on a wall or window. For outside use, enclose it in 1/2 inch PVC pipe with a tee in the center and end caps.
While we’re on the subject ofantennas, you may want an antenna for HF contacts. OCF stands for Off CenterFed, and it’s an inexpensive way to cover 40, 20, and 10 meters while notrequiring a lot of real estate to set up.
The design is based on a simple dipole, with a twist—you don’t feed it at the center, but off-center. All you need is 66 feet of wire, end insulators, and a 4:1 balun such as an LDG RBA-4:1.
The bigger your shack gets, themore power outlets you’ll need. In a typical shack you might have a 100 watt HFradio, a 50 watt 2m FM radio, an antenna tuner, and a QRP rig that all require13.8 volts—and your switching power supply may only have one or twoconnections.
SOTABeams Fuser 6 DC Distribution Boxkits incorporate PowerPole connectors and will let you connect up to five accessories to your power source. For safety, all of the connectors are individually fused and the box incorporates a polarity warning system to help avoid damage to your equipment.
All you need to build one is a soldering iron and solder; wire cutter, and screwdriver. Assembly time is about one hour. A four-way kit is also available.
When you test radio equipment, you need a way to transmit without interfering with other stations. The Elecraft DL1 Dummy Load Kit is a general purpose, wideband dummy load that lets you perform bench-top testing and alignment before connecting to the antenna. An on-board RF detector allows you to calculate power output using a digital voltmeter.
Power rating for the dummy loadis 100 watts momentary, 20 watts continuous.
Are you interested in digital communications modes? Unified Microsystems SCI-6 PC Sound Card Interface Kits can get you on PSK31, RTTY, WSJT, and other exciting digital modes by utilizing your PC’s internal sound card. Connect to your PC and radio, and make contacts using software such as FLDIGI.
This kit contains ahigh-quality, double-sided circuit board with a solder mask and componentlegends for easy assembly using simple tools. A machined case is included,along with cable for your computer.
QRP means radio operating with lowpower—typically 5 watts or less. So why would Hams use low power? It’s easy andinexpensive to build QRP radios and accessories—ones you can take just aboutanywhere and operate on batteries.
ARRL’s book More QRP Poweris a project resource including articles from recent issues of QST and QEX magazines. It covers construction practices, transceivers, transmitters, receivers, accessories, antennas, and more. Presented here are dozens of projects and articles to help you assemble or improve a QRP station for home or travel.