[TowerTalk] Grounding

Jim Brown jim at audiosystemsgroup.com
Sat Sep 7 17:58:02 EDT 2019


On 9/7/2019 11:03 AM, Richard Smith wrote:

This reflector is plain text only, so no photos.

Radio related comment -- be sure to include any such towers in the NEC 
model for any vertical antennas. After I got my 120 ft tower up almost 9 
years ago, N6BV and NI6T each suggested to me (and separately, not at 
the same time) that I check for interaction between it and my existing 
160 Tee vertical. Even though the tower is about 200 ft from the Tee, it 
acts as a nice passive reflector, giving me several dB going south!

I also have 1/4 wave wires for 160 sloping from the tower, insulated 
from the tower and fed from the base against elevated radials. I feed 
them one at a time, which also gives me a few dB in the direction of the 
slope, the tower acting as a reflector. AND -- if short the Tee, it acts 
as a reflector for those antennas, kicking their lobe about 40 degrees 
north to JA and EU.

Another point. I have high dipoles for 80, 40, and 30M, all fed with 
coax. Each has a choke inline optimized for 160M so that the feedline 
doesn't interact with the 160 antennas.

73, Jim K9YC


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