Trumpy,
Sorry, we're a bit busy at the Pentagon today. There are 2 basic types of antennas (OK there are literally thousands, but 2 basic types everyone uses)
The most common is the dipole. This is a piece of wire, great antenna and with a few minor "tweeks" is what I run. The formulas are fairly simple for this one.
You design antennas in increments of wavelengths.
Full wavelength = 984/frequency in MHZ, or in your case 984/26=37.85 feet
1/2 wavelength = 468/frequency in mhz or 468/26=18,
1/4 wavelength = 234/26= 9 feet.
A Yagi antenna (looks like your typical TV type) is made up of at least 3 elements. The one in the middle is called the "Driven" element and is usually 1/2 wavelength long, in your case, as above it would be 18 feet. The driven element is the one you connect your receiver transmitter to.
The long element behind the driven element is called the "Reflector" and is longer than the driven by some mathematical coefficient, most of my friends use 10%, so in this case it would be 18 feet plus 10% or 19'8"
The short element is called the "director" and like the reflector is a mathematical reflection like the reflector. If you use 10% it would be 16'6".
You can compound the Yagi with more directors and reflectors and it will help a bit.
Yagi's of this size we find aluminum is great, but feel free to manufacture out of bamboo with the copper wires taped/ty-wrapped to it.
Hope this gives you some direction, of course I'd never transmit without checking and really fine tuning with an SWR meter, and I'm certain you realize this. Also, these things aren't nearly as critical for only a receiver, again I'm certain you know this, but for others who may wander in.
Lemme know if you need anything further if I can be of assistance.
George AF4JH
