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. Here is the link to his VHF Delta Loop.
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 link provided describe this in full. The images underneath also provide full detail on how I constructed my version of this antenna.
Finally: I could access all the repeaters in my area with this antenna about 2 meters from the ground. I will do further tests and will provide the information in a future posting. 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.
PS. Apology for the quality of the photos especially the shadow reflections in the images.
