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ANTENNAS FOR 100 POUND DXPEDITIONS

5 REFERENCE ANTENNAS Before we begin investigating the performance of antennas we might use on a 100 Pound DXpedition we should look at the performance of some standard antenna designs. (Note that these standard antenna designs may also make fine antennas for our purposes!) This will give us a baseline from which we might compare antennas. The two antenna types to be discussed are a •

Quarter wave vertical antenna – This is a ground mounted antenna fed about 29 inches above ground with 16 radials.

Vertical dipole antenna – This is an antenna that does not require a radial system, is center fed, and can be deployed in even small areas.

An antenna of each type is modeled for all five bands 10, 12, 15, 17, and 20 meters. We begin with the quarter-wave vertical. 5.1

Quarter-wave verticals The following antennas are modeled with simple runs of AWG 16 wire. Antennas serving bands 10-20 meters such antennas can be easily constructed with a simple fishing pole holding up the vertical element and radials tied to trees or stakes. Though presented here as a “reference” antenna, these antennas could be used on a 100 Pound DXpedition. The space required to fully deploy the antennas is greater than what we typically expect to have, but if the space is available these antennas are fine choices giving good value for weight, size, and performance. I have used a “fishing pole vertical” for 40 meters (which is also good on 15 meters) and 80 meters on several trips with only two elevated radials with very good results. Since 20-foot fishing poles are available from major sporting good outlets for very little money, these antennas are also a very cost effective way to get on the air in that remote location. The following reference antennas are shown with 16 radials. Even four radials provide a surprisingly good antenna. The reader is encouraged to model these antennas for themselves. In the mean time, we spend the next few sections discussing these simple antennas for 10 through 20 meter bands.

5.1.1 10 meter Quarter-wave Vertical with Radials A full-sized quarter-wave vertical with radials is one of the simplest antennas to make or model. This example is a 10m vertical antenna with 16 radials. The antenna is fed, and its radials emanate from, a height of 29 inches. This puts the top of the antenna about 12 feet off the ground, easily held by a modestly sized collapsible fishing pole. A Black Widow pole 13 foot in length (with a closed length of 45.5 inches) is less than $11, for example. Longer poles up to 20 feet cost under $20. Such poles would make fine masts to hold up the upper-end of one of these quarter wave verticals. The model image for this antenna appears below.

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Antennas for 100 Pound DXpeditions - volume 1  

Computer-based antenna modeling and direct experience with lightweight portable antenna systems. Volume 1: Selected high band antennas [20-6...

Antennas for 100 Pound DXpeditions - volume 1  

Computer-based antenna modeling and direct experience with lightweight portable antenna systems. Volume 1: Selected high band antennas [20-6...

Profile for ne1rd
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