When I began construction of a dedicated 8-Circle Receive Array antenna system for the low bands (160m – 40m) some time ago (see part one in this series for details), I knew that I’d have to locate the new antenna system as far away from my tower and other transmitting antennas as possible to avoid overloading, pattern distortion and pickup of re-radiated noise by the new receive system. The picture above shows the antenna layout plan that I have been building to for some time now. My tower is in back of the house and the Low Band Receive Array System from DX Engineering that I am building is at the very front of our property. This provides the maximum separation between it and the transmitting antennas. The final element of my antenna build plan is to re-install our SteppIR BigIR Vertical Antenna at the side corner of our lot to separate it from the other antennas as well.
Placing antennas on the other side of our house required me to build a second shack entry and grounding point. The picture above shows the new entry point ready to accept feedlines and control cables. The first step in its construction was to install 3″ PVC conduits to get the feedlines from the woods in front of our house to the shack entry point and then through the outside of the house.
The next step was to construct the grounding system for the entry point. I again used one of the excellent Ground Bar Kits from Storm Copper. This was attached to the side of my house and it will provide grounding for the feedline for the SteppIR BigIR Vertical Antenna when it is re-installed. I installed an PolyPhaser Static Coax Lightening Protector on the Storm Ground Bar so that you can see how that element is mounted on the Ground Bar.
It is very important to have a good single point earth ground to provide lightning protection and a path for static electricity build up on your antennas to sink to ground. I used a standard 5/8″ x 8 ft electrical ground rod driven about 7 ft into the soil to provide the earth ground for my second shack entry point. This ground rod is connected to the Storm Ground Bar via a heavy ground cable (right side of the rod) and a crimp-on lug. The heavy copper ground cable to the left of the rod bonds the second shack entry ground to our electrical service entrance ground and to the tower and antenna grounding systems at the back of our house. This cable runs around the outside perimeter of our house and terminates on an 8 ft electrical ground rod approximately every 10 ft. The bare copper bonding cable is also buried a few inches in the soil which hides it and lowers the system’s resistance to ground somewhat. Note the use of clamps and a crimped lug to make all of the connections in the pictures above. Using mechanical connections of these types is essential and you should never solder ground connections as a lightening hit will instantly vaporize soldered connections. The resulting interruption of the connection to ground is very dangerous.
My Low Band Receive System uses a 75 ohm feedline and thus requires a 75 ohm Coaxial Lightening Protector which I got from DX Engineering. I also needed a means to provide static suppression for the control lines to the Receive System and to my BigIR Vertical. I used a Copper Ground Rod Clamp from Alpha-Delta to attach these items directly to the ground rod at the entry point. This required some minor modifications to the mounting brackets for the 75 ohm static suppressor and the Control Line Static Suppressor from ArraySolutions. Stainless steel hardware was used to fasten everything together to complete the installation. The resulting system worked out quite well is ready to accept the feedline and control cable from the receive system which I hope to complete this coming weekend.
– Fred (AB1OC)