Delta Loop Design, Construction & Kits
Delta Loops are very practical single band HF antennas. Typically, they are arranged with equal length sides (an equilateral triangle) - having a horizontal side at the top or the base. For instance, Figures: A, B & C have the horizontal side as their base, while Figures D & E feature the horizontal component at the top of the antenna. Thus, Figures A, B & C require a single support and Figures D & E require two tall supports.
How to Calculate the Length of a Delta Loop
Delta loops require a full wavelength of wire (1005/frequency = feet or , for instance 1005/14.200 = 70.77”). The feedpoint impedance will range from 70 ohms to 100 ohms. Either a matching section of 75 ohm coax can be deployed - or, even better, a 4:1 balun can be used.
For operators looking for gain over a standard dipole, the delta loop is an excellent choice (nearly .5 db gain over a dipole). Most of the radiation tends to be on the horizontal components. Thus, of the two vertically polarized (Fig. B & E) -Fig. E would be the top DX performer with more radiated power higher off the ground. Figure E., again, requires two tall supports and, to minimize detuning and unbalancing, the feedline needs to be pulled away from the feedpoint by 90 degrees. Figure B., on the other hand, is still an excellent performer when it comes to DXing and is highly recommended for its relative ease of construction and installation. This B & E are the choice for DXers and amongst A, C & D - A & C are veritable “cloud warmers’ while D will have a first skip range of approximately 400 miles.
Maximum radiation from all Delta Loops will be at 90 degrees from both sides of the plane of the loop. These antenna also typically work very well on their second harmonic; i.e. a Delta Loop for 14.000 MHz will also work well on 28.000 MHz. But, remember they are not multiband antennas and other than second harmonic performance do not expect multiband performance.
Ideal Heights for Delta Loops Top Support Are:
40m - Greater than 60’
30m - Greater than 45’
20m - Greater than 30’
17m - Greater than 17’
10m - Greater than 15’
Typical Delta Loop Designs
(see image below)
Delta Loop Kits by Amateur Radio Supplies
Our Delta Loop kit are designed to give everything you need to build your own antenna. You simply supply the support and the rope.