Don, W9IU, does almost all the antenna assembly and I do most of the "on the tower" work. Most of the elements were preassembled, because of the crate size. When the antenna assembly started, we had to clear enough room to work on the antennas. 
The above picture shows the C-51XR assembled and mounted at the tower base. This made it easy to work on the feed points and dress the coax down the boom. The next picture shows C-31XR assembled on the ground. 
The baluns used were suggest by Jay, WX0B, and made it more economical as a total project. I wanted to seperately feed each band on the antennas, so they were available to multiple radios during the contests. With this in mind I needed a total of 10 baluns. I didn't want the balun cost to be too excessive, so I built my own. 
The baluns were built using RG-174 wrapped around a ferrite core (FT-240-61). The balun can be seen mounted to the bottom of the boom. Actually it is heavily taped to the boom... The 20 and 15 meter feed points of the C-31XR antenna needs shunt coils. The 15 meter element (left side in the picture) uses a long one loop coil and the 20 meter (right side of the picture) uses a 7 loop coil to match 50 ohms. 
This picture is of the 40 meter feedpoint. The shunt coil is attached to the incoming feedline (from the balun) and the relay is then attached to the 40 meter element. Make sure you have the antenna perfectly tuned before you mount the antenna on the mast, as getting to this box requires 10 foot arms - Hi Hi !! |