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DL6WU Long boom Yagi design tools

DL6WU-OD.xlt

Overview

This is an Excel spreadsheet template to design DL6WU Yagi antennas based on the following references by Guenter Hoch, DL6WU:

and supplemented by direct information from DL6WU.

There are a large number of tools to assist with the design of long boom Yagis as described by Guenter Hoch, DL6WU. When comparing the outputs of these tools for identical inputs, there are differences that suggest departures from Guenter's design concepts. DL6WU-OD.xlt is an Excel spreadsheet template that provides a convenient method of developing, saving and documenting a design in a modern desktop application, and seeks to precisely follow Guenter's design concepts.

Figure 1 shows a screen shot of an example 2m DL6WU Yagi design in mm dimensions.

Figure 1: Example calculation in mm dimensions.

Figure 2 shows a screen shot of an example 70cm DL6WU Yagi design in inch dimensions.

Figure 2: Example calculation in inch dimensions.

This spreadsheet includes user functions written in VBA and derived from the program dl6wu-gg.bas on 17 July 2006. Table 1 is the change history from that file.

Table1: Change history from dl6wu-gg.bas at 17 July 2006
Original program by Jerry Haigwood KY4Z and Bob Stein,
   W6NBI 1983-86
Modifications by Ian White G3SEK 1986
Modifications recommended by DL6WU 1988
Modifications to reflector lengths (longer) 04/1989
PC version only -                                  |
   element spacings from table instead of formula  |
   metric dimension changed to mm instead of cm,   |
   menu selections by single keypress,             | G3SEK 06/89
   screen preview of dimensions                    |
   many line number changes                        |

Line 1250 corrected to show correct                |
electrical boom length in design summary           |
for Yagi's up to 14 elements.                      | GW7KYT 10/2000
Line 1522, reactance formula corrected             |
(-320 missing in original).                        |

Lines 1200-130 corrected correctly!                | G3SEK 09/2003

This derivation is produced and published with permission of Ian White (G3SEK, GM3SEK).

The intention with this spreadsheet was to faithfully implement the algorithms and data from the program dl6wu-gg.bas which is believed to best capture Guenter Hoch's design concepts. The program dl6wu-gg.bas used an algorithm for stacking distances that is probably sourced from W1JR. This spreadsheet uses DL6WU's recommended algorithm for optimal stacking distance, and a more accurate method of estimating the beamwidth of antennas (from which the stacking distance is calculated). These changes were made in consulation with Guenter Hoch and Ian White.

Square boom correction factor

The boom correction factors incorporated in the spreadsheet are those from dl6wu-gg.bas and were derived from experimental data.

A request was received to incorporate provision for calculating element corrections for a square section conductive boom using W9CF's Equivalent diameter of Rectangular Cross Section Conductor applet. W9CF's equivalence is designed around charge distribution for longitudinal currents, and is applicable to the Yagi elements but not to the boom (because the current is not predominantly longitudinal). The appropriate factor might well be similar, but not for the reasons given, and therefore not with the same accuracy.

Whilst accurate boom correction factors for square section booms would be of great interest, I have not yet seen the results of a soundly based method.

Defects

Please notify defects to owen at vk1od.net.

Change history

Installation

Download the file DL6WU-OD.xlt and save it in your Excel templates directory.

Templates are usually stored in the Templates folder, in the XLStart folder, or in the alternate startup folder. The easiest way to find the location of your Templates folder is to open a new workbook and attempt to save it as a template, noting the location of the default directory that is offered by Excel.

Once the template is installed, to create a new model based on the template, from the menu choose File/New and select DL6WU-OD.xlt as the template. (If you cannot see the template, it hasn't been installed properly, see above.

Digitally signed macros

The template contains macros with digital signature by VK1OD. The Certifying Authority certificate for this signature can be imported by clicking here using Microsoft Internet Explorer (do not use another browser for this purpose).

File checksums

Table 2: File checksums.
DL6WU-OD.xlt
md5sum 058daee6770eb656d8337f798e02089a
sha1sum 751ad1b2249149abb488ae172f8e810d8c573ef4

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