This is an ideal project for beginner radio amateurs that would like to construct their first antenna.
There are various designs on the Internet for 2 m Delta Loop antennas. I wanted something that can be erected easily anywhere and in no time. It should double as a fixed, portable and travel antenna and must function as an indoor and outdoor antenna. I decided to build the antenna as described by K2ZS. Unfortunately his web-site is not functional any more. I do however have a printed copy of his VHF Delta Loop where he describe this project. See images below.
The length of wire used in a delta loop antenna is determined using 1005/[frequency in Mhz.] so a loop for use on 145.500 Mhz simplex would be:
1005/145.500 = 6907 feet = 2105.2mm
The length can be divided by 3 for a delta loop or 4 for a quad style loop. For my delta loop that meant the wire would have to be about 702mm per side for a delta loop and 526mm for a quad style loop.
The quarter wavelength matching transformer would be 1/4 of that length multiplied by .67 to compensate for the velocity factor of the 75 ohm cable. Calculation = 2105mm divided by 4 x .67 = 353mm. In this case the stub should be around 353 mm from the connector to the attachment point on the loop. Keep in mind that those formulas are for ideal conditions like the antenna being mounted outdoors and in the clear so plan on starting long and trimming for resonance.
I am not going to go into full detail on how to construct this antenna as the images describe this in full. The images underneath also provide full detail on how I constructed my version of this antenna. Important: For optimal performance try and get the antenna up as high as possible from the ground and away from metal objects and other antennas that could interfere with the 2m Delta Loop Antenna.
Finally: I could access all the local repeaters in my area with this antenna about 2 meters from the ground. This antenna can easily be built for any VHF/UHF frequency. I enjoy building this antenna. It can easily fit into my carry bag and is easy to fold up or to install.
Original Article from K2ZS:
(Click on images for larger view.)
PS. Apology for the quality of the photos especially the shadow reflections in the images.
