Preliminary Studies of Long-Boom Yagis for 420-450 MHz--Or
Fly Me to the Moon. . .

L. B. Cebik, W4RNL

There are numerous long-boom Yagi designs, but little study of them using the latest antenna modeling software (NEC-4). This study is a small beginning of the process of analyzing the salient performance features of the various designs using models from my small collection. The effort arose from my own interest in determining if one might develop a "perfect" Yagi, and for this reason, it is strictly preliminary. The perfect Yagi does not yet exist.

Long-boom Yagis have an equally long history, but the late 1980s and the early 1990s are the period of the most rapid advances in their design. DL6WU, K1FO, DJ9BV, W1JR, and SM5BSZ are only some of the most noted calls associated with individual or families of Yagis susceptible to mathematical design algorithms. We shall sample efforts from each of these groundbreaking designers. Indeed, we shall sample 10 Yagis, 9 of which are long boom efforts, and one is an explanation of why these notes are only preliminary.

My procedures will be straightforward. I modeled each Yagi design using NEC-4. Some wide-band designs covering all or most of the 70-cm band required slight re-scaling to center the passband. In some instances, the designs had been optimized for one or the other end of the band. In a few cases, the initial model had used NEC-2. By the time we increase frequency to the 70-cm band, there is an offset between NEC-2 and NEC-4 amounting to 5-10 MHz. NEC-4 has revised algorithms for element ends and for the feedpoint split, and is considered more accurate in critical cases. To be fair to the potential of a given design, it was necessary--wherever possible--to so center a design within the band that the operating or 2:1 SWR bandwidth either is in the band or covers all of it and that the peak performance characteristics lie within the band. This latter factor allows anyone to re-scale an array's peak performance region to any desired portion of the band.

Since the models do not include conductive booms, the model descriptions appended to this study represent arrays whose elements are well insulated and isolated from any conductive boom. One can construct an array directly from the model adhering to those conditions. However, if alternative element diameters or alternative boom-mounting methods are required, the builder must apply appropriate compensation techniques. A summary of those techniques and some of the algorithms required for the work appear in "Scaling and Adjusting VHF/UHF Yagis" at my web site (..), with some of the techniques appearing in Chapter 7 of the RSGB volume The VHF/UHF DX Book, edited by Ian White, G3SEK.

For each array, I shall provide similar data. First comes a set of vital statistics giving both the physical size of the array and any special modeling notes, followed by an outline sketch of the antenna. Except for a couple of narrow-band designs, each antenna will have a table of modeled performance figures for 420, 435, and 450 MHz. The data will include both horizontal and vertical beamwidths and forward-to-sidelobe ratios in addition to the more expected gain and front-to-back ratios. Following each table will be sample E-plane and H-plane (free-space) patterns for the arrays. I shall add a frequency sweep of the gain and the 180-degree front-to-back ratio and another sweep of the resistance, reactance, and SWR curves. Finally, I shall add some commentary on the array, although the data itself should make most of the commentary obvious.

Because the long-boom Yagis come in various sizes with respect to both the number of elements and the overall boomlength, direct comparison from one design to the next is at best an uncertain enterprise. However, the aggregate results will permit us to draw a number of interesting conclusions about the present state of design and the future of long-boom Yagi design.

Evaluating Long-Boom Yagi Designs

Although somewhat tedious, the process of developing both physical and performance data on long-boom Yagis is very straightforward. Evaluatively interpreting that data is another matter. Evaluation often rests upon the intended communications task for which one creates a beam. Even within the confines of a given task, there is no fixed agreement on the order in which to place the various facets of Yagi performance.

Forward gain and the front-to-back ratio (taken either as the 180-degree ratio or the worst-case front-to-back ratio) are the most common prime performance figures. Very often, beamwidth--both horizontal and vertical--are simply presumed and go unexamined. Until recently, the forward front-to-sidelobe ratio has been ignored. (See "Long-Boom Yagi Sidelobe Suppression" in the Proceedings of the 2002 Southeastern VHF Society, pp. 67-124, for a discussion of this topic.) Nonetheless, some aspects of overall pattern shape as it shifts from one end of the operating passband to the other require non-quantitative commentary at the present stage in the development of studies of long-boom Yagi performance.

It is possible to develop some ad hoc measures of Yagi size that permit a few comparisons and detection of some general trends. Therefore, we shall look at the element density of the designs, using the first 21 directors as a guide--since 21 directors comprise the shortest of the designs that we shall examine. We shall also take a measure of the gain-to-element ratio and the gain-to-boom-length ratio. We shall develop these numbers for either 432 MHz (for the narrow-band designs) or 435 MHz (for the wide-band designs). None of these figures has any long-term merit, but they do permit us to reach a few interesting conclusions about the designs at hand. We shall also look at the range of gain and the range of front-to-back ratios across the operating passband wherever these numbers are notable for the builder.

In the end, comparison and evaluation can only be suggestive and not authoritative, especially for the radio amateur. Every long-boom Yagi goes through two phases in amateur hands. First is the feeling that there is nothing superior to "this" beam as it passes its final tests and adjustments and is declared operational. After some use, the inveterate beam builder acquires the equally strong feeling that there must be a superior design that just has to be built. I shall reserve further general comments for the concluding section.

The tabular data on the performance for each array will include the following categories.

Forward Gain (dBi): The free-space gain of the forward lobe.
180-Deg F-B (dB): The 180-degree front-to-back ratio.
Worst-Case F-B (dB): The worst case front-to-back ratio relative to the entire rear
horizontal semi-circle.
Horiz. B-W (deg): The E-plane -3-dB beamwidth of the forward lobe.
Vert. B-W (deg): The H-plane -3-dB beamwidth of the forward lobe.
Horiz. F-SL (dB): The E-plane forward main-lobe-to-strongest-secondary-lobe ratio.
Vert. F-SL (dB): The H-plane forward main-lobe-to-strongest-secondary-lobe ratio.
Note: The notation (+B) indicates forward pattern bulges or merged lobes.
Feed Z (R+/-jX Ohms): The driven element feedpoint impedance.
SWR (n Ohms): The SWR relative to a given reference impedance.

1. A 32-Element DL6WU Yagi

Guenter Hoch, DL6WU, is perhaps the most noted designer of long-boom VHF and UHF Yagis. His work appears in its most developed form in Chapters 7 and 10 of The VHF/UHF DX Book. In addition, there are numerous programs for designing his beams, the most recent of which is an interesting EXCEL spreadsheet available from David Tanner, VK3AUU, whose own designs will appear later in this study. Since the algorithms describing the DL6WU beams are so well known, we may focus on the data instead of the theory. As with all succeeding data, any references to dimensions in wavelengths are for 432 MHz.

Basic Data:
No. of Elements: 32                     Boom Length: 7505.2 mm or 10.81 WL
Element Diameter: 4 mm                  Model Segmentation: 19 segments/element
Element Density: .00454 elements/mm of boomlength


Basic Performance Data: Frequency
Category                        420                     435                     450
Forward Gain (dBi)              18.07                   19.75                   19.21
180-Deg F-B (dB)                20.61                   25.28                   29.35
Worst-Case F-B (dB)     20.61                   25.28                   23.44
Horiz. B-W (deg)                23.0                    19.8                    18.6
Vert. B-W (deg)         23.6                    20.2                    19.0
Horiz. F-SL (dB)                13.52                   16.46                   21.76 (+B)
Vert. F-SL (dB)         12.31                   15.44                   19.20 (+B)
Feed Z (R+/-jX Ohms)    49.96 - j 9.24          52.24 + j 4.98          39.83 + j 9.64
SWR (50 Ohms)           1.203                   1.113                   1.367

435-MHz Gain/Element:                   0.617
435-MHz Gain/Boom Length (WL):          1.827

The gain of the wide-band DL6WU array varies by over 1.8 dB across the band, with the peak gain at 440 MHz. Near-peak gain and maximum front-to-back ratio coincide at 438 MHz. For narrow-band use, one may re-scale the array from about 438 MHz to the desired operating frequency within the 70-cm band. Since the frequency sweeps are at 2-MHz intervals, some peaks do not appear. Flattened curves normally mean that a peak value occurs between the point of the flattened line.

The change in the pattern shape--especially evident in the H-plane patterns--as we move across the band reflects the changing roles of the driver and the first director. As we increase frequency, the myriad of secondary lobes shifts rearward as the current magnitude on the first director exceeds that on the driver itself, making the first director a slaved driver for the array. This phenomenon is a common feature of almost all wide-band Yagi arrays.

The front-to-sidelobe ratio of the DL6WU array is fairly low--well under 20 dB--for all but the last 5 MHz of the band. Again, in common with many wide-band arrays, the first forward sidelobes become bulges on the main lobe, changing its shape from a "tear drop" into a "bullet." Hence, at 450 MHz, the first distinct forward sidelobe is actually the second forward sidelobe in both the E-plane and the H-plane.

The DL6WU array, at whatever length the builder chooses, has become a sort of touchstone against which to measure virtually all long-boom Yagis. Its wide bandwidth, easy scaling, and generally good performance for any number of elements from about 10 upward have made this array popular. Perhaps the strongest reservation concerns the relatively low front-to-sidelobe performance, but the DL6WU array is not alone in this difficulty.

2. A 31-Element HyGain/W1JR Yagi

When I picked up the following HyGain Yagi design from their former web site, Joe Reisert, W1JR, wrote me to note that he had done the original design for the company. I have adapted the model to 4-mm elements from the original HyGain model that used 3/16" elements (0.1575" vs. 0.1875"). The SWR curve proved smoother using the 4-mm elements. W1JR has published other long-boom Yagi designs in various journals, so this sample is but one expression of his work over the years. The element density is roughly similar to that of the DL6WU design, although the arrangement of elements differs. See the appended model descriptions for details of the director placement. With respect to the reflector, driver, and first director arrangement, DL6WU wide-band designs use element spacings of 0.20 wavelength and 0.075 wavelength for these rearmost elements. The W1JR design uses spacings of 0.178 wavelength and 0.0715 wavelength to achieve its feedpoint impedance control. The long-boom Yagi designer has a wide variety of reflector/driver/first-director arrangements from which to choose, even within the category of 50-Ohm driven elements.

Basic Data:
No. of Elements: 31                     Boom Length: 6990.0 mm or 10.07 WL
Element Diameter: 4 mm                  Model Segmentation: 19 segments/element
Element Density: .00471 elements/mm of boomlength


Basic Performance Data: Frequency
Category                        420                     435                     450
Forward Gain (dBi)              17.23                   18.97                   19.60
180-Deg F-B (dB)                20.64                   32.41                   23.77
Worst-Case F-B (dB)     20.51                   26.40                   23.77
Horiz. B-W (deg)                25.2                    22.4                    20.2
Vert. B-W (deg)         26.2                    23.0                    20.8
Horiz. F-SL (dB)                13.31                   16.95                   19.45
Vert. F-SL (dB)         11.99                   15.72                   18.40
Feed Z (R+/-jX Ohms)    40.81 - j14.01          46.99 - j 8.68          29.65 - j 7.17
SWR (50 Ohms)           1.446                   1.208                   1.739

435-MHz Gain/Element:                   0.612
435-MHz Gain/Boom Length (WL):          1.883

The HyGain/W1JR array has characteristics quite similar to those of the DL6WU version. The gain peaks high in the overall passband at 19.64 dBi, although the shorter boom and 1-smaller element count results in a 2.4-dB range of gain across the band. The 180-degree front-to-back ratio shows peaks, although the worst-case value remains fairly constant above the low end of the band. The 50-Ohm SWR is not as uniformly low as in the DL6WU wide-band array, but the values are generally acceptable. However, the SWR begins to climb in the region of highest gain.

As one might expect, the gain per boom length unit is higher, but the gain per element is lower. Overall, the element density is similar to that of the DL6WU design, even though the element placement differs between the two designs. As we shall gradually discover, element density has a role to play in the more general pattern shape. The present sample has front-to-sidelobe ratios very comparable to those of the DL6WU Yagi. Finally, the beamwidth across the band is slightly wider than one might generally expect from a reduction in element count of only 1 and a boom reduction of only 7% relative to our first sample Yagi.

Nevertheless, one can re-scale the array for any desired frequency within the passband in order to maximize performance in that region. If operation above that frequency is necessary, the next step would be to adjust the reflector, driver, and first director lengths and spacing to achieve an acceptable feedpoint impedance.

3. A 27-Element DJ9BV Yagi

Rainer Bertelsmeier, DJ9BV, championed the use of a multiple-reflector Yagi, claiming better performance. The sample that I have uses 27 elements, but 4 of them are reflector elements set out in a flat plane perpendicular to the remaining elements. Hence, the array has only 22 directors. The natural presumption is that the added reflectors will enhance the front-to-back ratio. However, if the flat-plane reflectors assist the array, it is more likely in the gain category. Both operating bandwidth and the front-to-back ratio tend to degrade relative to our first two sample arrays.

Basic Data:
No. of Elements: 27                     Boom Length: 5295.0 mm or 7.63 WL
Element Diameter: 4.6 mm                        Model Segmentation: 19 segments/element
Element Density: .00434 elements/mm of boomlength



Basic Performance Data: Frequency
Category                        420                     435                     450
Forward Gain (dBi)              17.52                   18.74                   17.43
180-Deg F-B (dB)                19.00                   22.59                   16.94
Worst-Case F-B (dB)     19.00                   22.59                   16.94
Horiz. B-W (deg)                25.6                    22.2                    21.6
Vert. B-W (deg)         26.6                    23.0                    22.4
Horiz. F-SL (dB)                15.49                   17.25                   20.77 (+B)
Vert. F-SL (dB)         13.76                   15.45                   18.25 (+B)
Feed Z (R+/-jX Ohms)    37.66 - j26.66          36.30 - j19.92          25.18 - j22.46
SWR (50 Ohms)           1.994                   1.751                   2.488

435-MHz Gain/Element:                   0.694
435-MHz Gain/Boom Length (WL):          2.546

I set the dimensions of the DJ9BV array for mid-band to test the overall operating bandwidth. The design falls somewhere between a narrow-band and a wide-band design, covering about 2/3 of the 70-cm band with acceptable front-to-back ratio and 50-Ohm SWR values. However, with judicious revision of the reflector/driver/first-director region, one might improve the SWR curve considerably. The array arose in an era still wedded to the folded dipole driven element as a means of maximizing gain while establishing a 50-Ohm SWR curve.

Relative to our first two samples, the overall pattern shape shows improvements to the front-to-sidelobe ratio. However, the 450-MHz pattern has bulges that one likely should not ignore and which show a melding of the main lobe and the first forward sidelobes. Hence, the high front-to-sidelobe ratio at that frequency has dubious value.

The gain peaks between 435 and 440 MHz, although the front-to-back ratio peaks at a lower frequency. The high levels of gain per unit of boom length and per element have two facets. First, they are naturally higher than the longer arrays with more directors. However, they are especially high, given that the director count is so low relative to the overall design. The design ultimately shows that by narrowing the operating passband, one can achieve a higher gain figure with fewer elements.

Nonetheless, as we shall see in a later sample, there may be better configurations for multiple reflectors in order to suppress forward sidelobes more effectively, especially in the H-plane.

4. A 40-Element K1FO Yagi

Steve Powlishen, K1FO, has developed a series of VHF and UHF Yagis that ARRL has featured in the Antenna Book for several editions. (See pp. 18-21 through 18-32 in the 19th edition.) One of the strong merits of his work is that he provides both basic information and detailed adjustments for constructed versions, thus guiding the builder in great detail. The sample that we shall explore here is a 40-element free-space version, that is, a modeled version with no correctives for a system of element-to-boom mounting.

Basic Data:
No. of Elements: 40                     Boom Length: 9251.9 mm or 13.33 WL
Element Diameter: 4.7 mm                        Model Segmentation: 19 segments/element
Element Density: .00506 elements/mm of boomlength


Basic Performance Data: Frequency
Category                        420                     435                     450
Forward Gain (dBi)              19.06                   20.80                   20.48
180-Deg F-B (dB)                21.89                   32.81                   23.55
Worst-Case F-B (dB)     21.86                   29.93                   23.55
Horiz. B-W (deg)                20.8                    18.2                    16.4
Vert. B-W (deg)         21.4                    18.4                    16.6
Horiz. F-SL (dB)                13.52                   15.97                   24.77 (+B)
Vert. F-SL (dB)         12.58                   15.16                   22.79 (+B)
Feed Z (R+/-jX Ohms)    27.43 - j12.56          31.05 - j 0.89          20.73 + j11.47
SWR (28 Ohms)           1.568                   1.114                   1.744

435-MHz Gain/Element:                   0.520
435-MHz Gain/Boom Length (WL):          1.560

The gain factors of the K1FO design naturally decrease relative to earlier sample designs, since the addition of each new director shows a decreasing increment of gain advance. However, the array shows better than 20-dBi free-space gain over more than half the 70-cm band, with peak gain appearing in the 440-442-MHz region. By now, it should be apparent that standard wide-band long-boom Yagi design has this characteristic. Both the 180-degree and the worst-case front-to-back ratios are better than 21 dB across the band.

The gain advance in the long K1FO design is offset partially by generally poorer suppression of the forward side lobes. Indeed, relative to forward sidelobe suppression, the best region of operation appears to be at the upper end of the band, where the pattern takes on the bullet shape, but the narrow beamwidth tends to ameliorate the effect of the bulges created by merged forward lobes. In this case, there may be two sets of forward lobes merged with the main lobe. In concert with the earliest of our samples, as we increase the operating frequency within the design passband, the front-to-side ratio at about 90 degrees to the main lobe decreases, as the first director takes greater control of the current distribution in the directors.

Although the K1FO design has relatively wide operating characteristics, with less than 2-dB change in gain across the band, there is one troublesome aspect to the design. The low design feedpoint impedance--between 25 and 30 Ohms--doubles the losses incurred by any less-than-perfect mechanical junctions at the feedpoint. Models do not analyze the reduction in gain occasioned by such losses. Hence, it becomes important for the user to perform tests and analyses that will determine the total power loss of these factors. The division of power between the radiation antenna and the losses always degrades as we lower the feedpoint impedance. Folded dipoles do not cure the problem, since the impedance transformation includes loss as well as radiation resistance. The ultimate cure, beyond perfecting every mechanical connection in the system, lies in minimizing the number of such connections.

5. A 26-Element SM5BSZ Yagi

Although wide-band Yagis offer advantages in terms of replication ease and the ability to move a selected operating point to a desired frequency, they do not obtain the maximum gain from a given number of elements. Lief Asbrink, SM5BSZ, has developed (among his many contributions to VHF and UHF work) a narrow-band long-boom Yagi. He uses 26 elements on a 7429-mm boom, that is, 6 fewer elements on the same boom length used in the DL6WU array that we explored at the beginning. The cost of the exercise is a beam with a very narrow operating bandwidth. In fact, the design is not much good only a couple of MHz away from the 432-MHz design frequency. But at that frequency, it shines.

In part, the effectiveness of the design stems from the use of fatter than usual elements: 10 mm. As well, note the lower density level of the elements in the following table of basic data. Within the performance data--given only for 432 MHz--note the relatively high values of the gain per element figure and the gain per wavelength of boom figure. Because the array is for narrow-band use, the pattern data will only be for 432 MHz, and the performance graphs will cover only 430-434 MHz.

Basic Data:
No. of Elements: 26                     Boom Length: 7429.4 mm or 10.70 WL
Element Diameter: 10 mm                 Model Segmentation: 19 segments/element
Element Density: .00353 elements/mm of boomlength


Basic Performance Data: Frequency
Category                        432
Forward Gain (dBi)              20.52
180-Deg F-B (dB)                21.29
Worst-Case F-B (dB)     21.26
Horiz. B-W (deg)                18.0
Vert. B-W (deg)         18.4
Horiz. F-SL (dB)                17.14
Vert. F-SL (dB)         16.21
Feed Z (R+/-jX Ohms)    36.69 - j 1.36
SWR (37 Ohms)           1.038

435-MHz Gain/Element:                   0.789
435-MHz Gain/Boom Length (WL):          1.916

It is likely that only a master antenna builder may replicate this antenna adequately, especially if one must make adjustments for the method of element-to-boom mounting. However, the array does illustrate how much gain one may squeeze out of the least number of elements on a given boom length. As well, comparing this array's peak performance to the wide-band arrays of relevantly similar lengths, we can obtain some idea of how much performance at a given frequency that we sacrifice to obtain the wide-band characteristics designed into those arrays. These are aspects of array performance too little appreciated by many operators trying to decide upon an array for a given task. In the end, if one builds the antenna oneself, the final decision must be a considered balance of the desired performance level vs. the degree of difficulty in replicating a design, with an honest consideration of one's shop skills and tools. Since SM5BSZ is "in the industry," he undoubtedly has access to the finest fabrication tools and has a track record that suggests his skills are unsurpassed.

6. A 43-Element VE7BQH Yagi

VE7BQH, Lionel Edwards, developed a "ladder" array that Bill Buchanan, WB4WEN, brought to my attention. To provide some basis for comparison, I adapted the design to the 70-cm band, although that was not its original band. As a result, the model that we shall explore uses a wire diameter close to that of AWG #18 wire. (Re-scaled for the 220-MHz band, the wire size would approximate #12.) One must picture the structure of the antenna as two ropes with wire elements between them. This array is the longest in the collection we are examining, both in terms of the number of elements and in terms of boom length. However, its element density is similar to the values obtained from the DL6WU and W1JR arrays. Unlike all of the other Yagis in this collection, it does not use aluminum tubing, but instead employs copper wire. Like the SM5BSZ entry, we shall restrict our glimpse to its design frequency, 432 MHz, although we shall extend the performance sweeps to include 428 to 441 MHz. The reference impedance for the SWR curve is 28 Ohms.

Basic Data:
No. of Elements: 43                     Boom Length: 10042.1 mm or 14.47 WL
Element Diameter: 1.1 mm                Model Segmentation: 19 segments/element
Element Density: .00499 elements/mm of boomlength


Basic Performance Data: Frequency
Category                        432
Forward Gain (dBi)              20.95
180-Deg F-B (dB)                30.26
Worst-Case F-B (dB)             29.93
Horiz. B-W (deg)                15.2
Vert. B-W (deg)         15.4
Horiz. F-SL (dB)                13.55
Vert. F-SL (dB)         12.87
Feed Z (R+/-jX Ohms)    31.66 - j13.84
SWR (28 Ohms)           1.610

435-MHz Gain/Element:                   0.487
435-MHz Gain/Boom Length (WL):          1.448

Although the original 2-meter version of this array was designed to solve the boom-length problem at that lower frequency region, the 70-cm version that I have modeled gives us an example of what we can do with wire. Although it is much longer than the SM5BSZ narrow-band array, the VE7BQH Yagi uses very thin elements. Element diameter and the level of mutual coupling between elements play important roles in developing gain from a given arrangement of elements. I am often surprised by the number of arrays that I encounter where one or more directors are almost inactive. If you wish to hand optimize a Yagi design, pay close attention to the current levels on each element and watch for pattern changes as the levels vary during your adjustments. Of course, we can monitor current on all elements of a Yagi more easily in models than we can with physical elements.

The SM5BSZ and the VE7BQH Yagis are two radically different approaches to narrow-band Yagi design. Both produce high gain, but both are deficient in terms of overall pattern shape, especially with respect to the suppression of side lobes. Perhaps other design approaches can yield somewhat better results.

7. A 41-Element VK3AUU Yagi

David Tanner, VK3AUU has done some extensive design work in a somewhat different direction from the one taken by other designers of wide-band Yagis. First, he has striven to improve--at least for part of the operating passband--the overall pattern shape, including the suppression of forward sidelobes. Second, he has attempted to optimize the spacing of the reflector, driver, and first director in an interesting manner to achieve a very low 50-Ohm SWR across the passband--that is, all of the 70-cm band. Although the effort is related to the WA3FET/NW3Z techniques for the optimized wideband antenna set-up (OWA), there are certain distinct features to the VK3AUU design.

DL6WU used spacings of 0.200 and 0.075 wavelength, respectively, for the reflector/driver and driver/first-director. Most other designers have followed suit, with minor variations in the reflector/driver spacing, but with a driver/first-director spacing above 0.075. The typical OWA array will use a reflector/driver spacing of just over 0.1 wavelength, with a driver/first-director spacing in the vicinity of about 0.055 wavelength. Of course, the exact spacings depend to some extent upon the length-to-diameter ratio of the elements in order to achieve a smooth 50-Ohm SWR curve with maximum values under about 1.3:1 across a passband. On a band as wide as 70 cm, obtaining the desired curve with normal element diameters (1/8" to 1/4") is not easy. As well, the second and third directors of a standard OWA configuration have roughly equal lengths.

VK3AUU employs a wider reflector/driver spacing (0.19-0.20 wavelength) together with a very narrow driver/first-director spacing (0.033 to 0.038 wavelength) to obtain very broad SWR curves. The models that we shall examine are adapted from 2-meter versions, and the elements have been standardized at a 4-mm diameter. We shall start with a planar Yagi having 41 elements.

Basic Data:
No. of Elements: 41                     Boom Length: 7723.3 mm or 11.13 WL
Element Diameter: 4 mm                  Model Segmentation: 19 segments/element
Element Density: .00622 elements/mm of boomlength


Basic Performance Data: Frequency
Category                        420                     435                     450
Forward Gain (dBi)              18.56                   19.73                   19.67
180-Deg F-B (dB)                22.30                   26.35                   25.17
Worst-Case F-B (dB)     22.30                   26.35                   25.17
Horiz. B-W (deg)                22.8                    20.6                    19.8
Vert. B-W (deg)         23.6                    21.2                    20.2
Horiz. F-SL (dB)                15.74                   19.52                   17.51
Vert. F-SL (dB)         14.57                   18.51                   16.26
Feed Z (R+/-jX Ohms)    49.14 - j 4.41          50.56 - j 1.41          44.39 - j 3.53
SWR (28 Ohms)           1.095                   1.031                   1.150

435-MHz Gain/Element:                   0.481
435-MHz Gain/Boom Length (WL):          1.773

One feature that the VK3AUU design shares in common with standard OWA techniques is the ability to center the performance characteristics of an array within an operating passband. Although not completely centered, the gain curve peaks at about 440 MHz, lower than most other wide-band designs.

The forward sidelobe suppression is not yet a full-band phenomenon. Rather, it peaks in the center third of the band and tapers off on either side of that region. Suppression is nearly 20 dB in the E-plane and slightly less in the H-plane. The suppression is superior to other wide-band designs in this study at 420 MHz. Unfortunately, the change of pattern in those designs from a teardrop to a bullet defeats an effective comparison at 450 MHz. However, it is notable that the VK3AUU design retains its tear drop pattern throughout the 70-cm band.

One key to the improvement of pattern shape is the higher element density used by VK3AUU. The element density of 0.00622 elements per mm is about 23% higher than the next most dense array (0.00506) in the collection of Yagis that we have so far studied. The boom length is barely longer than the DL6WU design, but VK3AUU includes 9 more elements, resulting in closer element spacing and consequential increases in element-to-element coupling. Since the weight of the elements is not a major factor in UHF arrays, adding more elements for a given boom length in order to improve pattern shape shows up mostly in fabrication time. The gain levels are equal or superior to those of the DL6WU array, with only a 1.3-dB variation across the 70-cm band.

8. A 32-Element VK3AUU Yagi With Added Reflectors

VK3AUU adapted the reflector scheme that I described in the sidelobe suppression study to his basic element scheme in an effort to further reduce forward sidelobes, especially in the H-plane. The result is a 32-element array with 3 reflectors and 28 directors on a 5500-mm boom. (Once more, my model is a 70-cm re-scaling of the designer's 2-meter array.) The 2 added directors are angled slightly to the rear of the normal reflector and produce significant results. In the original design using OWA techniques, I set the reflectors to have minimal effects on the feedpoint impedance relative to a basic array that used only 1 reflector. VK3AUU has chosen to slightly modify the rearmost elements to achieve the same results. The dimensions appear in the model descriptions appended to this study.

Basic Data:
No. of Elements: 32                     Boom Length: 5464.5 mm or 7.87 WL
Element Diameter: 4 mm                  Model Segmentation: 19 segments/element
Element Density: .00595 elements/mm of boomlength


Basic Performance Data: Frequency
Category                        420                     435                     450
Forward Gain (dBi)              17.98                   18.45                   18.08
180-Deg F-B (dB)                27.98                   35.41                   31.97
Worst-Case F-B (dB)     25.33                   32.65                   31.97
Horiz. B-W (deg)                25.4                    23.6                    23.0
Vert. B-W (deg)         26.4                    24.4                    23.8
Horiz. F-SL (dB)                19.59                   23.02                   22.26
Vert. F-SL (dB)         17.87                   21.18                   20.04
Feed Z (R+/-jX Ohms)    44.81 - j11.26          46.02 - j 5.89          39.94 + j 2.43
SWR (28 Ohms)           1.299                   1.160                   1.438

435-MHz Gain/Element:                   0.577
435-MHz Gain/Boom Length (WL):          2.343

In this array, the gain curve is almost perfectly centered in the overall passband. However, the patterns at 450 MHz have degraded slightly so that they are approaching the bullet shape that merges forward sidelobes into the main pattern. In some sense, then, the development of this offshoot array is not fully complete.

Nevertheless, the array improves both horizontal and vertical front-to-sidelobe ratios by over 4 dB relative to the 41-element planar array that we just examined. Except for the lowest portion of the band, the front-to-sidelobe ratio is better than 20 dB. The only other array with a similar boom length is the DJ9BV Yagi with its plane of 4 reflectors. The VK3AUU array with its "tilt-back" reflector system achieves nearly 6 dB better front-to-sidelobe ratios with only about 0.5 dB gain variation across the passband and comparable gain levels to the DJ9BV Yagi. The improvements accrue not only to the redesign of the added reflectors in accord with principles I laid out in the sidelobe suppression study, but as well to the increased element density. For similar boom lengths, the VK3AUU Yagi employs 6 additional directors.

9. A 12-Element OWA Yagi

We now come to the point of showing why the present study is preliminary. The search for a "perfect" Yagi includes not only the standard operating parameters of gain, front-to-back ratio, and SWR bandwidth. As well, it encompasses pattern shape. Pattern shape refers partly to the visual shape, that is, the ideal tear drop pattern. It also refers partly to the suppression of all sidelobes to the degree feasible.

To set a reference point for such a shape, I am adding to this study a Yagi design that is not a long-boom array as defined by the preceding examples. Indeed, the boom is under 3 wavelengths. The design is an OWA array scaled and adjusted from past 2-meter examples, but with 4-mm diameter elements. Stretching the 2-meter passband to cover the 70-cm band requires considerable adjustment, since the 4 MHz of 2 meters is only 12 of the 30 MHz of 70 cm. Still, it is a possible task.

Basic Data:
No. of Elements: 12                     Boom Length: 1997.7 mm or 2.88 WL
Element Diameter: 4 mm          Model Segmentation: 19 segments/element
Element Density: .00601 elements/mm of boomlength


Basic Performance Data: Frequency
Category                        420                     435                     450
Forward Gain (dBi)              13.16                   14.08                   13.95
180-Deg F-B (dB)                20.51                   23.59                   20.06
Worst-Case F-B (dB)             20.51                   23.59                   20.06
Horiz. B-W (deg)                41.8                    38.4                    35.6
Vert. B-W (deg)         47.2                    42.5                    39.2
Horiz. F-SL (dB)                20.81                   27.70                   23.63
Vert. F-SL (dB)         15.96                   18.60                   15.31
Feed Z (R+/-jX Ohms)    31.32 + j 5.34          48.76 + j14.78          30.05 - j 1.62
SWR (28 Ohms)           1.626                   1.349                   1.666

435-MHz Gain/Element:                   1.173
435-MHz Gain/Boom Length (WL):          4.890

Translating the 2-meter 12-element OWA Yagi to 70 cm has left some work yet to be done. The gain curve is not fully centered in the passband. As well, although the SWR curve has the characteristic OWA shape, the band-edge values are higher than desired. Moreover, the average value of the resistive component of the impedance might be increased slightly.

Nevertheless, the horizontal front-to-sidelobe ratio is greater than 20 dB across the band. As with the 2-meter version of this Yagi, the vertical front-to-sidelobe values lag seriously behind, although adding tilt-back reflectors would effect considerable improvement. The pattern shapes are consistently tear-drop across the band, although there is a bit of evidence at 420 MHz of main and sidelobe merging.

The use of this short-boom array (as measured on the 70-cm band) is to set a quasi-standard. The array shows what can be done across the band, especially with respect to pattern shape and horizontal sidelobe suppression. Although the VK3AUU 41-element array achieves equivalent horizontal sidelobe suppression for part of the band, it does not sustain that level of suppression across the entire band. Hence, there is further work to be done.

10. A 41-Element Hybrid OWA/VK3AUU Yagi

One key element in the OWA Yagi's ability to suppress horizontal sidelobes is the construction of the entire 5-element main cell of the array. The rearmost 3 elements largely set the feedpoint impedance and bandwidth. However, the 2nd and 3rd directors--sometimes called stabilizing directors--are of equal or near equal length. Together with the elements to the rear, they provide a pattern-shaping effect that contributes to the sidelobe suppression. The VK3AUU 41-element Yagi achieves its results in part due to the element density. Perhaps it might be possible to create a hybrid using the first 5 elements from the OWA array and elements 6-41 of the VK3AUU array. With some adjustments, the result is our final design of the study. The question is whether we can use this technique to create a design with all of the desired properties of a nearly perfect Yagi.

Basic Data:
No. of Elements: 41                     Boom Length: 7727.3 mm or 11.14 WL
Element Diameter: 4 mm                  Model Segmentation: 19 segments/element
Element Density: .00621 elements/mm of boomlength


Basic Performance Data: Frequency
Category                        420                     435                     450
Forward Gain (dBi)              18.31                   19.36                   19.24
180-Deg F-B (dB)                27.18                   28.78                   30.36
Worst-Case F-B (dB)     27.18                   28.78                   25.35
Horiz. B-W (deg)                22.6                    20.4                    20.0
Vert. B-W (deg)         23.4                    21.0                    20.4
Horiz. F-SL (dB)                16.01                   20.57                   16.67
Vert. F-SL (dB)         14.87                   19.59                   15.37
Feed Z (R+/-jX Ohms)    46.14 - j 5.15          45.42 + j 2.34          45.64 + j 5.38
SWR (28 Ohms)           1.143                   1.114                   1.156

435-MHz Gain/Element:                   0.472
435-MHz Gain/Boom Length (WL):          1.738

The hybrid array achieves about 1 dB of further sidelobe suppression over the original VK3AUU 41-element Yagi, but the suppression is not close to uniform across the entire band. As well, the gain has suffered a small decrease, although this is both marginal and expected relative to the OWA core of elements. As well, the gain curve is not well centered, but parallels the curve for the original VK3AUU beam design. The front-to-back ratio--taken as either the 180-degree or the worst-case value--is smoother across the band. Hence, the results of the experiment are mixed, with some improvements and some deficiencies, but all at the margins of the performance of the 41-element VK3AUU Yagi.

In a more important sense, the experiment is a major failure. The creation of a hybrid array did not provide smooth sidelobe suppression all across the 70-cm band, as in the case of the small 12-element Yagi. However, this result was not wholly unexpected. The family of OWA Yagis for 2-meters grew in length by a complex procedure of adding one element at a time and adjusting it and the preceding director to achieve the desired combination of pattern shape, gain curve, and SWR curve. So far, I have uncovered no algorithm to automate this process. The spacing for each additional element is variable, and it may even be the case that the usual rule, by which we place a new director at an equal or greater space than the preceding one, might require discarding.

The entire study, then is preliminary, because much more work remains ahead in the search for the nearly perfect Yagi.

Conclusions (So Far)

We may summarize the results of this preliminary study in the following set of entries in our notebooks.

Gain: We may obtain forward gain with an adequate front-to-back ratio in a variety of ways, depending on the operating bandwidth that we desire. The SM5BSZ array shows how to do this with a minimum number of fat elements for a given boom length, while the long VE7BQH ladder Yagi shows how to replicate the gain using thin wire. For wide bandwidths, there is little to choose among the DL6WU, W1JR, or K1FO arrays--adjusted for similar boom lengths and number of elements--except for certain preferences of feedpoint impedance or other minor factors.

Operating Bandwidth: For most long-boom UHF Yagi operations, bandwidth is not a major concern, since operations tend to cluster near certain specific frequencies. However, for the home beam builder, a wide bandwidth offers greater assurance of successful replication of a given design, as well as ease of scaling the array from an initial design frequency to the one specifically desired. As well, it is more likely that the recalculation of elements for new element diameters or for insulated through-boom mounting will result in a working array whose performance is close to the values reported by the initial model.

Modeling: Almost all of the models in this study require more than 500 total segments to achieve adequate convergence of results. As well, for serious design work at UHF frequencies, NEC-4 is the modeling core of choice to avoid the frequency offset of NEC-2. (Even the best version of MININEC tend to calibrate the necessary frequency corrections to NEC-2. Hence, before using any MININEC program for serious UHF array design, be sure to calibrate it to NEC-4.) The upshot is that serious design efforts require a serious investment in software and the licenses that may go with a package.

Pattern Shape: The most interesting challenge yet to be faced in the improvement of long-boom Yagis lies in the area of achieving a consistent tear-drop pattern across the 70-cm band with improved forward sidelobe suppression. Initial experiments suggest that increased element density can go some distance toward this goal, but that element density alone may not achieve results that cover the entire band. Hence, there are an unlimited number of experiments that await us in the arena of using variable element spacing to see if we can extend the consistent E-plane patterns of shorter Yagis to long-boom arrays. Once we have reached the goal for E-plane patterns, improving the H-plane patterns should be straightforward through the use of added tilt-back reflectors.

In the end, I can do little better than to repeat myself: much more work remains ahead in the search for the nearly perfect long-boom Yagi.

Appendix: EZNEC Model Descriptions of Yagis Used in This Study

=============================================================================

1.  DL6WU 32 el 435 MHz                Frequency = 435  MHz.

Wire Loss: Aluminum -- Resistivity = 4E-08 ohm-m, Rel. Perm. = 1

              --------------- WIRES ---------------

Wire Conn. --- End 1 (x,y,z : mm)  Conn. --- End 2 (x,y,z : mm)   Dia(mm) Segs

1            0.000,170.300,  0.000         0.000,-170.30,  0.000 4.00E+00  19
2          138.800,165.000,  0.000       138.800,-165.00,  0.000 4.00E+00  19
3          190.800,150.800,  0.000       190.800,-150.80,  0.000 4.00E+00  19
4          315.800,149.600,  0.000       315.800,-149.60,  0.000 4.00E+00  19
5          465.000,147.800,  0.000       465.000,-147.80,  0.000 4.00E+00  19
6          638.400,146.100,  0.000       638.400,-146.10,  0.000 4.00E+00  19
7          832.800,144.600,  0.000       832.800,-144.60,  0.000 4.00E+00  19
8          1040.90,143.200,  0.000       1040.90,-143.20,  0.000 4.00E+00  19
9          1259.50,142.100,  0.000       1259.50,-142.10,  0.000 4.00E+00  19
10         1488.60,141.100,  0.000       1488.60,-141.10,  0.000 4.00E+00  19
11         1728.00,140.200,  0.000       1728.00,-140.20,  0.000 4.00E+00  19
12         1977.80,139.400,  0.000       1977.80,-139.40,  0.000 4.00E+00  19
13         2238.00,138.700,  0.000       2238.00,-138.70,  0.000 4.00E+00  19
14         2508.70,138.000,  0.000       2508.70,-138.00,  0.000 4.00E+00  19
15         2786.30,137.400,  0.000       2786.30,-137.40,  0.000 4.00E+00  19
16         3063.90,136.900,  0.000       3063.90,-136.90,  0.000 4.00E+00  19
17         3341.40,136.400,  0.000       3341.40,-136.40,  0.000 4.00E+00  19
18         3619.00,135.900,  0.000       3619.00,-135.90,  0.000 4.00E+00  19
19         3896.60,135.400,  0.000       3896.60,-135.40,  0.000 4.00E+00  19
20         4174.20,135.000,  0.000       4174.20,-135.00,  0.000 4.00E+00  19
21         4451.80,134.600,  0.000       4451.80,-134.60,  0.000 4.00E+00  19
22         4729.40,134.200,  0.000       4729.40,-134.20,  0.000 4.00E+00  19
23         5007.00,133.800,  0.000       5007.00,-133.80,  0.000 4.00E+00  19
24         5284.50,133.500,  0.000       5284.50,-133.50,  0.000 4.00E+00  19
25         5562.10,133.100,  0.000       5562.10,-133.10,  0.000 4.00E+00  19
26         5839.70,132.800,  0.000       5839.70,-132.80,  0.000 4.00E+00  19
27         6117.30,132.500,  0.000       6117.30,-132.50,  0.000 4.00E+00  19
28         6394.90,132.250,  0.000       6394.90,-132.25,  0.000 4.00E+00  19
29         6672.50,131.950,  0.000       6672.50,-131.95,  0.000 4.00E+00  19
30         6950.10,131.650,  0.000       6950.10,-131.65,  0.000 4.00E+00  19
31         7227.60,131.400,  0.000       7227.60,-131.40,  0.000 4.00E+00  19
32         7505.20,131.150,  0.000       7505.20,-131.15,  0.000 4.00E+00  19

              -------------- SOURCES --------------

Source    Wire      Wire #/Pct From End 1    Ampl.(V, A)  Phase(Deg.)  Type
          Seg.     Actual      (Specified)

1          10     2 / 50.00   (  2 / 50.00)      1.000       0.000       V

Ground type is Free Space

=============================================================================

2. HyGain/W1JR 432 31 el                      Frequency = 435  MHz.

Wire Loss: Aluminum -- Resistivity = 4E-08 ohm-m, Rel. Perm. = 1

              --------------- WIRES ---------------

Wire Conn. --- End 1 (x,y,z : mm)  Conn. --- End 2 (x,y,z : mm)   Dia(mm) Segs

1            0.000,167.290,  0.000         0.000,-167.29,  0.000 4.60E+00  19
2          122.738,162.653,  0.000       122.738,-162.65,  0.000 4.60E+00  19
3          172.028,151.925,  0.000       171.905,-151.93,  0.000 4.60E+00  19
4          294.763,148.832,  0.000       294.763,-148.83,  0.000 4.60E+00  19
5          438.765,145.739,  0.000       438.765,-145.74,  0.000 4.60E+00  19
6          607.891,144.193,  0.000       607.898,-144.19,  0.000 4.60E+00  19
7          794.413,142.742,  0.000       794.413,-142.74,  0.000 4.60E+00  19
8          997.366,140.425,  0.000       997.366,-140.43,  0.000 4.60E+00  19
9          1209.02,138.491,  0.000       1209.02,-138.49,  0.000 4.60E+00  19
10         1430.33,138.491,  0.000       1430.33,-138.49,  0.000 4.60E+00  19
11         1663.25,136.944,  0.000       1663.25,-136.94,  0.000 4.60E+00  19
12         1905.82,135.398,  0.000       1905.82,-135.40,  0.000 4.60E+00  19
13         2157.09,134.624,  0.000       2157.09,-134.62,  0.000 4.60E+00  19
14         2412.24,134.239,  0.000       2412.24,-134.24,  0.000 4.60E+00  19
15         2673.18,133.466,  0.000       2673.18,-133.47,  0.000 4.60E+00  19
16         2939.91,132.692,  0.000       2939.91,-132.69,  0.000 4.60E+00  19
17         3209.55,132.692,  0.000       3209.55,-132.69,  0.000 4.60E+00  19
18         3479.19,131.919,  0.000       3479.19,-131.92,  0.000 4.60E+00  19
19         3749.79,131.919,  0.000       3749.79,-131.92,  0.000 4.60E+00  19
20         4019.43,131.146,  0.000       4019.43,-131.15,  0.000 4.60E+00  19
21         4290.03,131.146,  0.000       4290.03,-131.15,  0.000 4.60E+00  19
22         4559.67,128.536,  0.000       4559.67,-128.54,  0.000 4.60E+00  19
23         4829.31,127.763,  0.000       4829.31,-127.76,  0.000 4.60E+00  19
24         5099.91,127.763,  0.000       5099.91,-127.76,  0.000 4.60E+00  19
25         5369.54,127.763,  0.000       5369.54,-127.76,  0.000 4.60E+00  19
26         5640.15,126.217,  0.000       5640.15,-126.22,  0.000 4.60E+00  19
27         5909.78,126.605,  0.000       5909.78,-126.61,  0.000 4.60E+00  19
28         6179.42,126.605,  0.000       6179.42,-126.61,  0.000 4.60E+00  19
29         6450.03,125.831,  0.000       6450.03,-125.83,  0.000 4.60E+00  19
30         6719.66,125.831,  0.000       6719.66,-125.83,  0.000 4.60E+00  19
31         6990.27,125.831,  0.000       6990.27,-125.83,  0.000 4.60E+00  19

              -------------- SOURCES --------------

Source    Wire      Wire #/Pct From End 1    Ampl.(V, A)  Phase(Deg.)  Type
          Seg.     Actual      (Specified)

1          10     2 / 50.00   (  2 / 50.00)      1.000       0.000       V

Ground type is Free Space

=============================================================================

3. DJ9BV BV70-7L 432 MHz                        Frequency = 435  MHz.

Wire Loss: Aluminum -- Resistivity = 4E-08 ohm-m, Rel. Perm. = 1

              --------------- WIRES ---------------

Wire Conn. --- End 1 (x,y,z : mm)  Conn. --- End 2 (x,y,z : mm)   Dia(mm) Segs

1            0.000,-170.00,225.000         0.000,170.000,225.000 4.00E+00  19
2            0.000,-170.00, 75.000         0.000,170.000, 75.000 4.00E+00  19
3            0.000,-170.00,-75.000         0.000,170.000,-75.000 4.00E+00  19
4            0.000,-170.00,-225.00         0.000,170.000,-225.00 4.00E+00  19
5          115.000,-160.00,  0.000       115.000,160.000,  0.000 4.00E+00  19
6          170.000,-153.50,  0.000       170.000,153.500,  0.000 4.00E+00  19
7          295.000,-150.50,  0.000       295.000,150.500,  0.000 4.00E+00  19
8          445.000,-148.50,  0.000       445.000,148.000,  0.000 4.00E+00  19
9          620.000,-147.00,  0.000       620.000,147.000,  0.000 4.00E+00  19
10         815.000,-146.00,  0.000       815.000,146.000,  0.000 4.00E+00  19
11         1025.00,-144.50,  0.000       1025.00,144.500,  0.000 4.00E+00  19
12         1245.00,-143.00,  0.000       1245.00,143.000,  0.000 4.00E+00  19
13         1475.00,-141.00,  0.000       1475.00,141.000,  0.000 4.00E+00  19
14         1715.00,-141.00,  0.000       1715.00,141.000,  0.000 4.00E+00  19
15         1965.00,-141.00,  0.000       1965.00,141.000,  0.000 4.00E+00  19
16         2225.00,-139.00,  0.000       2225.00,139.000,  0.000 4.00E+00  19
17         2495.00,-139.00,  0.000       2495.00,139.000,  0.000 4.00E+00  19
18         2775.00,-139.00,  0.000       2775.00,139.000,  0.000 4.00E+00  19
19         3055.00,-137.50,  0.000       3055.00,137.500,  0.000 4.00E+00  19
20         3335.00,-137.50,  0.000       3335.00,137.500,  0.000 4.00E+00  19
21         3615.00,-137.50,  0.000       3615.00,137.500,  0.000 4.00E+00  19
22         3895.00,-136.00,  0.000       3895.00,136.000,  0.000 4.00E+00  19
23         4175.00,-136.00,  0.000       4175.00,136.000,  0.000 4.00E+00  19
24         4455.00,-136.00,  0.000       4455.00,136.000,  0.000 4.00E+00  19
25         4735.00,-135.00,  0.000       4735.00,135.000,  0.000 4.00E+00  19
26         5015.00,-135.00,  0.000       5015.00,135.000,  0.000 4.00E+00  19
27         5295.00,-135.00,  0.000       5295.00,135.000,  0.000 4.00E+00  19

              -------------- SOURCES --------------

Source    Wire      Wire #/Pct From End 1    Ampl.(V, A)  Phase(Deg.)  Type
          Seg.     Actual      (Specified)

1          10     5 / 50.00   (  5 / 50.00)      1.000       0.000       V

Ground type is Free Space

=============================================================================

4. K1FO Free-Space 432 design                   Frequency = 432  MHz.

Wire Loss: Aluminum -- Resistivity = 4E-08 ohm-m, Rel. Perm. = 1

              --------------- WIRES ---------------

Wire Conn. --- End 1 (x,y,z : mm)  Conn. --- End 2 (x,y,z : mm)   Dia(mm) Segs

1            0.000,168.055,  0.000         0.000,-168.05,  0.000 4.71E+00  19
2          102.810,165.089,  0.000       102.810,-165.09,  0.000 4.71E+00  19
3          144.330,155.698,  0.000       144.330,-155.70,  0.000 4.71E+00  19
4          221.437,151.249,  0.000       221.437,-151.25,  0.000 4.71E+00  19
5          328.201,147.789,  0.000       328.201,-147.79,  0.000 4.71E+00  19
6          460.668,145.812,  0.000       460.668,-145.81,  0.000 4.71E+00  19
7          614.883,143.835,  0.000       614.883,-143.84,  0.000 4.71E+00  19
8          788.870,142.847,  0.000       788.870,-142.85,  0.000 4.71E+00  19
9          978.673,141.858,  0.000       978.673,-141.86,  0.000 4.71E+00  19
10         1182.32,140.870,  0.000       1182.32,-140.87,  0.000 4.71E+00  19
11         1397.82,139.881,  0.000       1397.82,-139.88,  0.000 4.71E+00  19
12         1623.21,138.892,  0.000       1623.21,-138.89,  0.000 4.71E+00  19
13         1857.50,137.904,  0.000       1857.50,-137.90,  0.000 4.71E+00  19
14         2097.72,137.410,  0.000       2097.72,-137.41,  0.000 4.71E+00  19
15         2345.85,136.915,  0.000       2345.85,-136.92,  0.000 4.71E+00  19
16         2598.92,136.421,  0.000       2598.92,-136.42,  0.000 4.71E+00  19
17         2856.93,135.927,  0.000       2856.93,-135.93,  0.000 4.71E+00  19
18         3117.91,135.432,  0.000       3117.91,-135.43,  0.000 4.71E+00  19
19         3382.85,134.938,  0.000       3382.85,-134.94,  0.000 4.71E+00  19
20         3650.75,134.444,  0.000       3650.75,-134.44,  0.000 4.71E+00  19
21         3921.61,133.950,  0.000       3921.61,-133.95,  0.000 4.71E+00  19
22         4193.46,133.455,  0.000       4193.46,-133.46,  0.000 4.71E+00  19
23         4468.28,132.961,  0.000       4468.28,-132.96,  0.000 4.71E+00  19
24         4743.10,132.961,  0.000       4743.10,-132.96,  0.000 4.71E+00  19
25         5020.89,132.467,  0.000       5020.89,-132.47,  0.000 4.71E+00  19
26         5298.67,132.467,  0.000       5298.67,-132.47,  0.000 4.71E+00  19
27         5577.45,131.973,  0.000       5577.45,-131.97,  0.000 4.71E+00  19
28         5857.21,131.973,  0.000       5857.21,-131.97,  0.000 4.71E+00  19
29         6137.96,131.478,  0.000       6137.96,-131.48,  0.000 4.71E+00  19
30         6419.70,131.478,  0.000       6419.70,-131.48,  0.000 4.71E+00  19
31         6701.44,130.984,  0.000       6701.44,-130.98,  0.000 4.71E+00  19
32         6983.18,130.984,  0.000       6983.18,-130.98,  0.000 4.71E+00  19
33         7265.90,130.490,  0.000       7265.90,-130.49,  0.000 4.71E+00  19
34         7548.63,130.490,  0.000       7548.63,-130.49,  0.000 4.71E+00  19
35         7831.36,129.995,  0.000       7831.36,-130.00,  0.000 4.71E+00  19
36         8115.08,129.995,  0.000       8115.08,-130.00,  0.000 4.71E+00  19
37         8398.79,129.501,  0.000       8398.79,-129.50,  0.000 4.71E+00  19
38         8682.51,129.501,  0.000       8682.51,-129.50,  0.000 4.71E+00  19
39         8966.22,129.007,  0.000       8966.22,-129.01,  0.000 4.71E+00  19
40         9251.92,129.007,  0.000       9251.92,-129.01,  0.000 4.71E+00  19

              -------------- SOURCES --------------

Source    Wire      Wire #/Pct From End 1    Ampl.(V, A)  Phase(Deg.)  Type
          Seg.     Actual      (Specified)

1          10     2 / 50.00   (  2 / 50.00)      1.000       0.000       V

Ground type is Free Space

=============================================================================

5. SM5BSZ 26-el 432 MHz                         Frequency = 432  MHz.

Wire Loss: Aluminum -- Resistivity = 4E-08 ohm-m, Rel. Perm. = 1

              --------------- WIRES ---------------

Wire Conn. --- End 1 (x,y,z : mm)  Conn. --- End 2 (x,y,z : mm)   Dia(mm) Segs

1            0.000,161.689,  0.000         0.000,-161.69,  0.000 1.00E+01  19
2          199.598,156.474,  0.000       199.598,-156.47,  0.000 1.00E+01  19
3          272.708,153.315,  0.000       272.708,-153.32,  0.000 1.00E+01  19
4          456.677,145.693,  0.000       456.677,-145.69,  0.000 1.00E+01  19
5          696.427,142.075,  0.000       696.427,-142.07,  0.000 1.00E+01  19
6          961.601,138.577,  0.000       961.601,-138.58,  0.000 1.00E+01  19
7          1263.05,135.693,  0.000       1263.05,-135.69,  0.000 1.00E+01  19
8          1575.39,133.940,  0.000       1575.39,-133.94,  0.000 1.00E+01  19
9          1887.06,132.676,  0.000       1887.06,-132.68,  0.000 1.00E+01  19
10         2206.07,131.604,  0.000       2206.07,-131.60,  0.000 1.00E+01  19
11         2525.12,130.660,  0.000       2525.12,-130.66,  0.000 1.00E+01  19
12         2847.01,129.601,  0.000       2847.01,-129.60,  0.000 1.00E+01  19
13         3174.21,128.579,  0.000       3174.21,-128.58,  0.000 1.00E+01  19
14         3502.56,127.808,  0.000       3502.56,-127.81,  0.000 1.00E+01  19
15         3831.20,127.191,  0.000       3831.20,-127.19,  0.000 1.00E+01  19
16         4160.04,126.592,  0.000       4160.04,-126.59,  0.000 1.00E+01  19
17         4489.54,125.870,  0.000       4489.54,-125.87,  0.000 1.00E+01  19
18         4822.54,124.914,  0.000       4822.54,-124.91,  0.000 1.00E+01  19
19         5157.94,123.992,  0.000       5157.94,-123.99,  0.000 1.00E+01  19
20         5492.39,123.535,  0.000       5492.39,-123.54,  0.000 1.00E+01  19
21         5828.46,123.460,  0.000       5828.46,-123.46,  0.000 1.00E+01  19
22         6154.77,124.262,  0.000       6154.77,-124.26,  0.000 1.00E+01  19
23         6469.18,126.082,  0.000       6469.18,-126.08,  0.000 1.00E+01  19
24         6805.75,124.226,  0.000       6805.75,-124.23,  0.000 1.00E+01  19
25         7133.67,123.389,  0.000       7133.67,-123.39,  0.000 1.00E+01  19
26         7429.41,131.275,  0.000       7429.41,-131.27,  0.000 1.00E+01  19

              -------------- SOURCES --------------

Source    Wire      Wire #/Pct From End 1    Ampl.(V, A)  Phase(Deg.)  Type
          Seg.     Actual      (Specified)

1          10     2 / 50.00   (  2 / 50.00)      1.000       0.000       V

Ground type is Free Space

=============================================================================

6. VE7BQH 43-el "ladder" Yagi                        Frequency = 432  MHz.

Wire Loss: Aluminum -- Resistivity = 4E-08 ohm-m, Rel. Perm. = 1

              --------------- WIRES ---------------

Wire Conn. --- End 1 (x,y,z : mm)  Conn. --- End 2 (x,y,z : mm)   Dia(mm) Segs

1            0.000,170.873,  0.000         0.000,-170.87,  0.000 1.06E+00  19
2          104.400,165.673,  0.000       104.400,-165.67,  0.000 1.06E+00  19
3          145.546,162.555,  0.000       145.546,-162.55,  0.000 1.06E+00  19
4          224.865,159.242,  0.000       224.865,-159.24,  0.000 1.06E+00  19
5          333.284,155.954,  0.000       333.284,-155.95,  0.000 1.06E+00  19
6          470.410,155.767,  0.000       470.410,-155.77,  0.000 1.06E+00  19
7          624.401,153.524,  0.000       624.401,-153.52,  0.000 1.06E+00  19
8          803.685,153.354,  0.000       803.685,-153.35,  0.000 1.06E+00  19
9          993.819,153.932,  0.000       993.819,-153.93,  0.000 1.06E+00  19
10         1200.61,151.128,  0.000       1200.61,-151.13,  0.000 1.06E+00  19
11         1422.07,151.171,  0.000       1422.07,-151.17,  0.000 1.06E+00  19
12         1645.73,150.329,  0.000       1645.73,-150.33,  0.000 1.06E+00  19
13         1886.25,149.556,  0.000       1886.25,-149.56,  0.000 1.06E+00  19
14         2132.79,149.182,  0.000       2132.79,-149.18,  0.000 1.06E+00  19
15         2382.16,148.885,  0.000       2382.16,-148.88,  0.000 1.06E+00  19
16         2623.40,148.528,  0.000       2623.40,-148.53,  0.000 1.06E+00  19
17         2901.15,147.908,  0.000       2901.15,-147.91,  0.000 1.06E+00  19
18         3167.57,147.526,  0.000       3167.57,-147.53,  0.000 1.06E+00  19
19         3433.98,148.885,  0.000       3433.98,-148.88,  0.000 1.06E+00  19
20         3705.32,148.443,  0.000       3705.32,-148.44,  0.000 1.06E+00  19
21         3974.44,146.583,  0.000       3974.44,-146.58,  0.000 1.06E+00  19
22         4249.19,146.404,  0.000       4249.19,-146.40,  0.000 1.06E+00  19
23         4524.94,147.747,  0.000       4524.94,-147.75,  0.000 1.06E+00  19
24         4806.30,145.640,  0.000       4806.30,-145.64,  0.000 1.06E+00  19
25         5080.16,147.135,  0.000       5080.16,-147.14,  0.000 1.06E+00  19
26         5355.87,145.325,  0.000       5355.87,-145.33,  0.000 1.06E+00  19
27         5631.46,145.410,  0.000       5631.46,-145.41,  0.000 1.06E+00  19
28         5905.37,146.787,  0.000       5905.37,-146.79,  0.000 1.06E+00  19
29         6189.16,144.832,  0.000       6189.16,-144.83,  0.000 1.06E+00  19
30         6471.13,144.459,  0.000       6471.13,-144.46,  0.000 1.06E+00  19
31         6738.14,144.323,  0.000       6738.14,-144.32,  0.000 1.06E+00  19
32         7011.75,146.234,  0.000       7011.75,-146.23,  0.000 1.06E+00  19
33         7287.17,144.680,  0.000       7287.17,-144.68,  0.000 1.06E+00  19
34         7565.60,144.764,  0.000       7565.60,-144.76,  0.000 1.06E+00  19
35         7855.32,146.149,  0.000       7855.32,-146.15,  0.000 1.06E+00  19
36         8126.24,144.008,  0.000       8126.24,-144.01,  0.000 1.06E+00  19
37         8397.17,144.153,  0.000       8397.17,-144.15,  0.000 1.06E+00  19
38         8656.70,146.209,  0.000       8656.70,-146.21,  0.000 1.06E+00  19
39         8939.55,147.160,  0.000       8939.55,-147.16,  0.000 1.06E+00  19
40         9226.88,145.801,  0.000       9226.88,-145.80,  0.000 1.06E+00  19
41         9515.61,147.976,  0.000       9515.61,-147.98,  0.000 1.06E+00  19
42         9808.55,144.960,  0.000       9808.55,-144.96,  0.000 1.06E+00  19
43         10042.1,150.015,  0.000       10042.1,-150.01,  0.000 1.06E+00  19

              -------------- SOURCES --------------

Source    Wire      Wire #/Pct From End 1    Ampl.(V, A)  Phase(Deg.)  Type
          Seg.     Actual      (Specified)

1          10     2 / 50.00   (  2 / 50.00)      1.000       0.000       V

Ground type is Free Space

=============================================================================

7. VK3AUU 41 el                        Frequency = 432  MHz.

Wire Loss: Aluminum -- Resistivity = 4E-08 ohm-m, Rel. Perm. = 1

              --------------- WIRES ---------------

Wire Conn. --- End 1 (x,y,z : mm)  Conn. --- End 2 (x,y,z : mm)   Dia(mm) Segs

1            0.000,-167.05,  0.000         0.000,167.054,  0.000 4.00E+00  19
2          133.100,-169.89,  0.000       133.100,169.890,  0.000 4.00E+00  19
3          156.082,-153.60,  0.000       156.082,153.597,  0.000 4.00E+00  19
4          236.694,-151.55,  0.000       236.694,151.550,  0.000 4.00E+00  19
5          341.372,-149.79,  0.000       341.372,149.795,  0.000 4.00E+00  19
6          463.106,-148.04,  0.000       463.106,148.039,  0.000 4.00E+00  19
7          598.160,-146.28,  0.000       598.160,146.284,  0.000 4.00E+00  19
8          743.727,-144.82,  0.000       743.727,144.822,  0.000 4.00E+00  19
9          898.641,-143.36,  0.000       898.641,143.359,  0.000 4.00E+00  19
10         1061.50,-142.19,  0.000       1061.50,142.189,  0.000 4.00E+00  19
11         1231.37,-140.73,  0.000       1231.37,140.726,  0.000 4.00E+00  19
12         1407.31,-139.85,  0.000       1407.31,139.849,  0.000 4.00E+00  19
13         1588.86,-138.68,  0.000       1588.86,138.678,  0.000 4.00E+00  19
14         1775.79,-137.80,  0.000       1775.79,137.801,  0.000 4.00E+00  19
15         1967.38,-136.92,  0.000       1967.38,136.923,  0.000 4.00E+00  19
16         2163.19,-136.05,  0.000       2163.19,136.046,  0.000 4.00E+00  19
17         2363.43,-135.17,  0.000       2363.43,135.168,  0.000 4.00E+00  19
18         2567.18,-134.58,  0.000       2567.18,134.583,  0.000 4.00E+00  19
19         2774.67,-133.71,  0.000       2774.67,133.706,  0.000 4.00E+00  19
20         2985.42,-133.12,  0.000       2985.42,133.120,  0.000 4.00E+00  19
21         3199.45,-132.54,  0.000       3199.45,132.535,  0.000 4.00E+00  19
22         3416.52,-132.24,  0.000       3416.52,132.243,  0.000 4.00E+00  19
23         3636.62,-131.66,  0.000       3636.62,131.658,  0.000 4.00E+00  19
24         3859.30,-131.07,  0.000       3859.30,131.073,  0.000 4.00E+00  19
25         4084.78,-130.78,  0.000       4084.78,130.780,  0.000 4.00E+00  19
26         4312.59,-130.49,  0.000       4312.59,130.488,  0.000 4.00E+00  19
27         4542.98,-129.90,  0.000       4542.98,129.903,  0.000 4.00E+00  19
28         4775.93,-129.61,  0.000       4775.93,129.610,  0.000 4.00E+00  19
29         5011.69,-129.32,  0.000       5011.69,129.318,  0.000 4.00E+00  19
30         5221.61,-129.03,  0.000       5221.61,129.025,  0.000 4.00E+00  19
31         5435.15,-128.73,  0.000       5435.15,128.733,  0.000 4.00E+00  19
32         5652.20,-128.73,  0.000       5652.20,128.733,  0.000 4.00E+00  19
33         5872.77,-128.44,  0.000       5872.77,128.440,  0.000 4.00E+00  19
34         6096.85,-128.15,  0.000       6096.85,128.148,  0.000 4.00E+00  19
35         6321.51,-127.86,  0.000       6321.51,127.855,  0.000 4.00E+00  19
36         6552.60,-127.56,  0.000       6552.60,127.562,  0.000 4.00E+00  19
37         6787.21,-127.27,  0.000       6787.21,127.270,  0.000 4.00E+00  19
38         7020.65,-126.98,  0.000       7020.65,126.977,  0.000 4.00E+00  19
39         7257.59,-126.98,  0.000       7257.59,126.977,  0.000 4.00E+00  19
40         7488.69,-126.68,  0.000       7488.69,126.685,  0.000 4.00E+00  19
41         7723.30,-126.39,  0.000       7723.30,126.392,  0.000 4.00E+00  19

              -------------- SOURCES --------------

Source    Wire      Wire #/Pct From End 1    Ampl.(V, A)  Phase(Deg.)  Type
          Seg.     Actual      (Specified)

1          10     2 / 50.00   (  2 / 50.00)      1.000       0.000       V

Ground type is Free Space

=============================================================================

8. VK3AUU 32 el, triple reflector               Frequency = 432  MHz.

Wire Loss: Aluminum -- Resistivity = 4E-08 ohm-m, Rel. Perm. = 1

              --------------- WIRES ---------------

Wire Conn. --- End 1 (x,y,z : mm)  Conn. --- End 2 (x,y,z : mm)   Dia(mm) Segs

1          -16.312,-195.75,203.576       -16.312,195.747,203.576 4.00E+00  19
2          -16.312,-195.75,-203.58       -16.312,195.747,-203.58 4.00E+00  19
3            0.000,-169.97,  0.000         0.000,169.973,  0.000 4.00E+00  19
4          138.980,-169.16,  0.000       138.980,169.158,  0.000 4.00E+00  19
5          165.406,-155.94,  0.000       165.406,155.945,  0.000 4.00E+00  19
6          247.293,-153.82,  0.000       247.293,153.824,  0.000 4.00E+00  19
7          356.585,-151.87,  0.000       356.585,151.867,  0.000 4.00E+00  19
8          483.820,-150.07,  0.000       483.820,150.072,  0.000 4.00E+00  19
9          625.084,148.278,  0.000       625.084,-148.28,  0.000 4.00E+00  19
10         777.114,-146.81,  0.000       777.114,146.810,  0.000 4.00E+00  19
11         938.931,-145.18,  0.000       938.931,145.179,  0.000 4.00E+00  19
12         1109.23,-144.04,  0.000       1109.23,144.037,  0.000 4.00E+00  19
13         1286.71,-142.41,  0.000       1286.71,142.406,  0.000 4.00E+00  19
14         1470.38,-141.59,  0.000       1470.38,141.590,  0.000 4.00E+00  19
15         1660.26,-140.29,  0.000       1660.26,140.285,  0.000 4.00E+00  19
16         1855.68,-139.47,  0.000       1855.68,139.469,  0.000 4.00E+00  19
17         2055.67,-138.49,  0.000       2055.67,138.491,  0.000 4.00E+00  19
18         2260.22,-137.51,  0.000       2260.22,137.512,  0.000 4.00E+00  19
19         2469.67,-136.70,  0.000       2469.67,136.696,  0.000 4.00E+00  19
20         2682.38,-136.04,  0.000       2682.38,136.044,  0.000 4.00E+00  19
21         2899.33,-135.07,  0.000       2899.33,135.065,  0.000 4.00E+00  19
22         3119.55,-134.58,  0.000       3119.55,134.576,  0.000 4.00E+00  19
23         3343.03,-133.92,  0.000       3343.03,133.923,  0.000 4.00E+00  19
24         3570.09,-133.60,  0.000       3570.09,133.597,  0.000 4.00E+00  19
25         3800.09,-132.94,  0.000       3800.09,132.945,  0.000 4.00E+00  19
26         4032.71,-132.46,  0.000       4032.71,132.455,  0.000 4.00E+00  19
27         4268.25,-132.13,  0.000       4268.25,132.129,  0.000 4.00E+00  19
28         4506.41,-131.80,  0.000       4506.41,131.803,  0.000 4.00E+00  19
29         4746.86,131.150,  0.000       4746.86,-131.15,  0.000 4.00E+00  19
30         4990.56,-130.82,  0.000       4990.56,130.824,  0.000 4.00E+00  19
31         5242.09,-130.50,  0.000       5242.09,130.498,  0.000 4.00E+00  19
32         5464.59,-130.33,  0.000       5464.59,130.335,  0.000 4.00E+00  19

              -------------- SOURCES --------------

Source    Wire      Wire #/Pct From End 1    Ampl.(V, A)  Phase(Deg.)  Type
          Seg.     Actual      (Specified)

1          10     4 / 50.00   (  4 / 50.00)      1.000       0.000       V

Ground type is Free Space

=============================================================================

9. 12-el OWA Yagi 432 MHz                       Frequency = 435  MHz.

Wire Loss: Aluminum -- Resistivity = 4E-08 ohm-m, Rel. Perm. = 1

              --------------- WIRES ---------------

Wire Conn. --- End 1 (x,y,z : mm)  Conn. --- End 2 (x,y,z : mm)   Dia(mm) Segs

1            0.000,173.000,  0.000         0.000,-173.00,  0.000 4.00E+00  19
2           74.760,167.500,  0.000        74.760,-167.50,  0.000 4.00E+00  19
3          114.010,152.013,  0.000       114.010,-152.01,  0.000 4.00E+00  19
4          213.913,148.577,  0.000       213.913,-148.58,  0.000 4.00E+00  19
5          342.638,148.577,  0.000       342.638,-148.58,  0.000 4.00E+00  19
6          515.959,147.985,  0.000       515.959,-147.99,  0.000 4.00E+00  19
7          726.597,142.822,  0.000       726.597,-142.82,  0.000 4.00E+00  19
8          974.179,138.231,  0.000       974.179,-138.23,  0.000 4.00E+00  19
9          1230.90,134.650,  0.000       1230.90,-134.65,  0.000 4.00E+00  19
10         1497.68,131.088,  0.000       1497.68,-131.09,  0.000 4.00E+00  19
11         1762.79,127.507,  0.000       1762.79,-127.51,  0.000 4.00E+00  19
12         1997.69,122.402,  0.000       1997.69,-122.40,  0.000 4.00E+00  19

              -------------- SOURCES --------------

Source    Wire      Wire #/Pct From End 1    Ampl.(V, A)  Phase(Deg.)  Type
          Seg.     Actual      (Specified)

1          11     2 / 50.00   (  2 / 50.00)      1.000       0.000       V

Ground type is Free Space

=============================================================================

10. OWA-VK3AUU Hybrid Yagi                       Frequency = 435  MHz.

Wire Loss: Aluminum -- Resistivity = 4E-08 ohm-m, Rel. Perm. = 1

              --------------- WIRES ---------------

Wire Conn. --- End 1 (x,y,z : mm)  Conn. --- End 2 (x,y,z : mm)   Dia(mm) Segs

1            0.000,180.000,  0.000         0.000,-180.00,  0.000 4.00E+00  19
2           78.760,167.500,  0.000        78.760,-167.50,  0.000 4.00E+00  19
3          112.000,152.000,  0.000       112.000,-152.00,  0.000 4.00E+00  19
4          217.913,147.000,  0.000       217.913,-147.00,  0.000 4.00E+00  19
5          346.638,147.000,  0.000       346.638,-147.00,  0.000 4.00E+00  19
6          467.107,-148.04,  0.000       467.107,148.039,  0.000 4.00E+00  19
7          602.160,-146.28,  0.000       602.160,146.284,  0.000 4.00E+00  19
8          747.727,-144.82,  0.000       747.727,144.822,  0.000 4.00E+00  19
9          902.641,-143.36,  0.000       902.641,143.359,  0.000 4.00E+00  19
10         1065.50,-142.19,  0.000       1065.50,142.189,  0.000 4.00E+00  19
11         1235.37,-140.73,  0.000       1235.37,140.726,  0.000 4.00E+00  19
12         1411.31,-139.85,  0.000       1411.31,139.849,  0.000 4.00E+00  19
13         1592.86,-138.68,  0.000       1592.86,138.678,  0.000 4.00E+00  19
14         1779.79,-137.80,  0.000       1779.79,137.801,  0.000 4.00E+00  19
15         1971.38,-136.92,  0.000       1971.38,136.923,  0.000 4.00E+00  19
16         2167.19,-136.05,  0.000       2167.19,136.046,  0.000 4.00E+00  19
17         2367.43,-135.17,  0.000       2367.43,135.168,  0.000 4.00E+00  19
18         2571.18,-134.58,  0.000       2571.18,134.583,  0.000 4.00E+00  19
19         2778.67,-133.71,  0.000       2778.67,133.706,  0.000 4.00E+00  19
20         2989.42,-133.12,  0.000       2989.42,133.120,  0.000 4.00E+00  19
21         3203.45,-132.54,  0.000       3203.45,132.535,  0.000 4.00E+00  19
22         3420.52,-132.24,  0.000       3420.52,132.243,  0.000 4.00E+00  19
23         3640.62,-131.66,  0.000       3640.62,131.658,  0.000 4.00E+00  19
24         3863.30,-131.07,  0.000       3863.30,131.073,  0.000 4.00E+00  19
25         4088.78,-130.78,  0.000       4088.78,130.780,  0.000 4.00E+00  19
26         4316.59,-130.49,  0.000       4316.59,130.488,  0.000 4.00E+00  19
27         4546.98,-129.90,  0.000       4546.98,129.903,  0.000 4.00E+00  19
28         4779.93,-129.61,  0.000       4779.93,129.610,  0.000 4.00E+00  19
29         5015.69,-129.32,  0.000       5015.69,129.318,  0.000 4.00E+00  19
30         5225.61,-129.03,  0.000       5225.61,129.025,  0.000 4.00E+00  19
31         5439.15,-128.73,  0.000       5439.15,128.733,  0.000 4.00E+00  19
32         5656.20,-128.73,  0.000       5656.20,128.733,  0.000 4.00E+00  19
33         5876.77,-128.44,  0.000       5876.77,128.440,  0.000 4.00E+00  19
34         6100.85,-128.15,  0.000       6100.85,128.148,  0.000 4.00E+00  19
35         6325.51,-127.86,  0.000       6325.51,127.855,  0.000 4.00E+00  19
36         6556.60,-127.56,  0.000       6556.60,127.562,  0.000 4.00E+00  19
37         6791.21,-127.27,  0.000       6791.21,127.270,  0.000 4.00E+00  19
38         7024.65,-126.98,  0.000       7024.65,126.977,  0.000 4.00E+00  19
39         7261.59,-126.98,  0.000       7261.59,126.977,  0.000 4.00E+00  19
40         7492.69,-126.68,  0.000       7492.69,126.685,  0.000 4.00E+00  19
41         7727.30,-126.39,  0.000       7727.30,126.392,  0.000 4.00E+00  19

              -------------- SOURCES --------------

Source    Wire      Wire #/Pct From End 1    Ampl.(V, A)  Phase(Deg.)  Type
          Seg.     Actual      (Specified)

1          10     2 / 50.00   (  2 / 50.00)      1.000       0.000       V

Ground type is Free Space

=============================================================================

Updated 04-28-2003. © L. B. Cebik, W4RNL. First prepared for the South-East VHF Society, April 26, 2003. 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.

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Preliminary Studies of Long-Boom Yagis for 420-450 MHz--Or Fly Me to the Moon. . .