What is the approximate length of a delta loop antenna designed for 28.7 MHz?

Like a quad antenna, a delta loop is a full-wavelength wire loop. The only difference is its physical shape: a three-sided triangle rather than a four-sided square. Because it is a full-wave loop, the formula to calculate the total length of the wire is identical to that of a quad. To find the perimeter in metres, divide the constant 306 by the frequency in MHz. Calculating 306 / 28.7 MHz gives you approximately 10.66 metres. Since delta loops are closed-loop full-wave antennas, you must avoid using the half-wavelength or quarter-wavelength formulas that are meant for dipoles or vertical antennas.