Antenna Trail Exhibits

Antenna Trail Exhibits. Chatham Radio WCC – Receiving Station – Antenna Field Trail. , On this trail, you will see several different types of antennas that are representative of some of the antennas which were used at WCC, both here and at the transmitter site on Forest Beach in South Chatham. There are several half wave dipole antennas, a “Marconi T” antenna, and a “H over 2” antenna. , , Additionally, there is a “Yagi” beam antenna and an Off-Center-Fed (OCF) dipole antenna. These antennas are recent additions, installed for the use of the WCC Armature Radio Association (WCC ARA) and are not original to WCC. , , All Antennas you see are fully functional and often used by the SS Hope/WHNJ exhibit or the WCC ARA. , , Dipole Antennas , The dipole was the earliest type of antenna. It was invented by German physicist Heinrich Hertz around 1886. The dipole antenna or doublet is the simplest and most widely used class of antenna. Dipoles are resonant antennas, with standing waves of radio current flowing back and forth between their ends. The length of the dipole elements is determined by the wavelength of the radio frequency on which the antenna will be used. , , The most common form is the half-wave dipole, in which each of the two elements is approximately ¼ wavelength long, so the whole antenna is a half-wavelength long. , , Dipoles mounted horizontally (as is most common) will have gain in two opposing horizontal directions, perpendicular to the antenna axis, but nodes (directions of zero gain) at 90 from those directions. Neglecting electrical inefficiency, the antenna gain is equal to the directive gain, approximately 1.64 or 2.15dBi for a half-wave dipole. , , WCC had dipoles cut for the marine frequencies of 8MHz, 16MHz, 16MNz and 22 MHz at both this location and at the transmitter site. On this trail you will find dipoles that are cut for the Amateur Radio frequencies of 3.550MHz [80 meters ], 7.100MHz [40 meters], 10.110MHz [30 meters], 18.110MHz [17 meters], and 24.910MHz [12 meters]. ,