mirror of https://github.com/antenna2/cebik.git
124 lines
7.7 KiB
HTML
124 lines
7.7 KiB
HTML
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<html lang="en">
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<meta charset="UTF-8">
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<meta name="keywords" content="Horizontal Loop, HF Multi Band">
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<title>A Horizontal 80-Meter Multi-Band Loop Data Compendium</title>
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<link rel="stylesheet" href="../styles.css">
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<h1><img src="../images/yagicad.gif" align="left" width="125" height="62" border="2" vspace="5" hspace="10">ANTENNAS FROM THE GROUND UP<img src="../images/w4rnlwwr.gif" align="right" width="99" height="83" border="2" vspace="5" hspace="10"></h1>
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<h3>22. Ho-Ho-HOHPLs<br>
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or a Horizontal 80-Meter Multi-Band Loop Data Compendium</h3>
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</center>
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<center>
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<h3>L. B. Cebik, W4RNL</h3>
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<center>
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<img src="../images/colorbar.gif" align="middle" width="540" height="4">
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</center><br>
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<br>
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<p>The horizontally oriented, horizontally polarized 1 wavelength loop (at the lowest frequency of operation) (HOHPL) has become a fairly popular multi-band antenna. It has an advantage over the single wire that is 1/2 wavelength long at its lowest frequency of operation. Each side of the loop is only half as long as the doublet. But the loop also has a disadvantage: it requires 4 supports rather than 2. Which works better for a given ham location is something that only a careful survey of available land and supports will tell for certain. What can be done is to provide a compendium of patterns for a multi-band loop, similar to those provided in past episode for the 135' doublet, the 102' doublet, the OCF, and the 135' end-fed wire. Therefore, I modeled an 80-meter HOHPL, 70' on a side, using #12 copper wire. This length, when elevated 35' off the ground, was approximately resonant at 3.5 MHz.</p>
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<center>
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<img src="gup22-1.gif" width="497" height="280" border="2" vspace="5" hspace="9">
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</center>
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<p>The next question was where to feed the square. There are two reasonable locations: at a corner or midway along one side. Since the resulting patterns can be very different on some bands, there was no choice but to model the antenna both ways.</p>
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<p>Also modeled is a corner-fed (no phase line) N4PC loop at 50.7' per side. The N4PC loop is to the 102' G5RV what the 80-meter loops is to the 135' doublet. It has different patterns and somewhat higher elevation angles of maximum radiation than the larger loop.</p>
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<p>Although the HOHPL is a cloud-burner on 80 meters--like almost all low-level horizontal antennas--the performance on bands above the fundamental makes it very competitive among multi-band wires. An especially interesting feature is that the feedpoint impedance for either configuration is quite manageable on all bands. The resistive part of the impedance tops out at about 400 ohms, while only on 30 meters does the reactance exceed 200 ohms. With either 300-ohm or 450-ohm parallel transmission line, the antenna tuning unit (ATU) should have little difficulty establishing a match. The N4PC is only a little more of a matching challenge for the ATU.</p>
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<p>As always, the patterns are typical, but not precise, since modeling cannot reproduce the terrain and ground clutter of any given station. Feedpoint impedances are likewise ballpark numbers.</p>
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<h3>80 Meters: 3.6 MHz</h3>
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<center>
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<img src="gup22-2.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Corner-Fed: Z = 70 + j25 Ohms</b>
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<center>
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<img src="gup22-3.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Side-Fed: Z = 65 + j25 Ohms</b>
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<center>
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<img src="gup22-4.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>N4PC Corner-Fed: Z = 40 - j1215 Ohms</b>
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<h3>40 Meters: 7.1 MHz</h3>
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<center>
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<img src="gup22-5.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Corner-Fed: Z = 85 - j100 Ohms</b>
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<center>
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<img src="gup22-6.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Side-Fed: Z = 260 + j80 Ohms</b>
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<center>
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<img src="gup22-7.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>N4PC Corner-Fed: Z = 4060 + j1640 Ohms</b>
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<h3>30 Meters: 10.1 MHz</h3>
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<center>
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<img src="gup22-8.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Corner-Fed: Z = 360 - j560 Ohms</b>
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<center>
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<img src="gup22-9.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Side-Fed: Z = 280 - j535 Ohms</b>
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<center>
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<img src="gup22-10.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>N4PC Corner-Fed: Z = 105 + j25 Ohms</b>
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<h3>20 Meters: 14.1 MHz</h3>
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<center>
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<img src="gup22-11.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Corner-Fed: Z = 285 - j120 Ohms</b>
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<center>
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<img src="gup22-12.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Side-Fed: Z = 265 - j165 Ohms</b>
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<center>
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<img src="gup22-13.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>N4PC Corner-Fed: Z = 270 - j570 Ohms</b>
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<h3>17 Meters: 18.1 MHz</h3>
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<center>
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<img src="gup22-14.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Corner-Fed: Z = 370 + j205 Ohms</b>
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<center>
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<img src="gup22-15.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Side-Fed: Z = 405 + j175 Ohms</b>
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<center>
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<img src="gup22-16.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>N4PC Corner-Fed: Z = 780 - j1165 Ohms</b>
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<h3>15 Meters: 21.1 MHz</h3>
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<center>
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<img src="gup22-17.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Corner-Fed: Z = 240 - j105 Ohms</b>
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<center>
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<img src="gup22-18.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Side-Fed: Z = 405 - j125 Ohms</b>
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<center>
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<img src="gup22-19.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>N4PC Corner-Fed: Z = 575 + j810 Ohms</b>
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<h3>12 Meters: 24.95 MHz</h3>
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<center>
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<img src="gup22-20.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Corner-Fed: Z = 325 + j100 Ohms</b>
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<center>
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<img src="gup22-21.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Side-Fed: Z = 370 + j35 Ohms</b>
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<center>
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<img src="gup22-22.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>N4PC Corner-Fed: Z = 345 + j180 Ohms</b>
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<h3>10 Meters: 28.1 MHz</h3>
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<center>
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<img src="gup22-23.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Corner-Fed: Z = 215 - j145 Ohms</b>
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<center>
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<img src="gup22-24.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>Side-Fed: Z = 245 - j180 Ohms</b>
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<center>
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<img src="gup22-25.gif" width="640" height="480" border="2" vspace="5" hspace="9">
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</center><b>N4PC Corner-Fed: Z = 450 - j725 Ohms</b>
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<center>
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<img src="../images/colorbar.gif" align="middle" width="540" height="4">
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</center>
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<p><i>Updated 10-01-2000. © L. B. Cebik, W4RNL. Data may be used for personal purposes, but may not be reproduced for publication in print or any other medium without permission of the author.</i></p>
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<center>
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<img src="../images/colorbar.gif" align="middle" width="540" height="4">
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</center>
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<p><a href="groundup.html"><img src="../images/return.gif" align="bottom" width="40" height="40"> Go to series index page</a></p>
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<p><a href="../radio.html"><img src="../images/rtnhome.gif" align="bottom" width="40" height="40"> Return to Amateur Radio Page</a></p>
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<p class="topics-footer">Topics: <a href='../topics.html#hf-multi-band'>HF Multi Band</a>, <a href='../topics.html#horizontal-loop'>Horizontal Loop</a></p><br>
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