by Martin E. Meserve
VHF/UHF Yagi Antenna Quick Designer
This page is intended for users that want to experiment with a yagi design but do notneed all the rhetoric contained on the main
Yagi Design Page. This page assumes
that you have already read the information on the Yagi
Design Page and understand what each of the text boxes and selectors are for. This page minimizes all the
clicking, scrolling, and popups but still uses all of the same equations as the main
Yagi Design Page. Any changes to the
input data is immediately rendered in the design data at the bottom of the page.
Any output in a red font is usually a warning that you are trying to do something that it outside the capabilities
of the design program. That's OK, as the program isn't going to anything real wierd. However, in extreme cases, you might
get odd outputs, like negative numbers or "NAN" listings. Just try not to stray too far from the program capabilities.
The main restriction is to keep the required Gain between 11.8 and 21.6 dBd, and the Boom Length between 2.2 and 39 Wavelengths.
Other restrictions exist that are frequency dependent. They are listed in the input areas.
Use the following entry areas to define your antenna requirements. Specifying a Gain > 21.6 dBd or
a Boom Length > 39 λ will limit the design to 21.6 dBd Gain and Boom Length to 39 λ.
The page will operate below the lower limits, 11.8 dBd of gain and and 2.2 λ Boom Length, but the output data
may not be accurate. Input dimensions can be mixed and matched as all input data is converted to λ
before calculations are done.
The Design Information, lower left drawing, is based on your input
data from the previous section. The Antenna Dimension, lower right drawing,
is based on your design specifications. You can use the buttons, on the top right and left of the
Antenna Dimension drawing, to change from US/Imperial
(default) to Metric. The drawing windows below may change size, based
on your design requirements.