[BC] RF absorption by foliage

[Lewis Munn]

Alan,
 
I just finished some ground system work on a Class IV station.  Shunt-fed tower.  Original installation was for about a 100 watt level...just some #6 wire, to the wire ground ring, and many wires loose since it had been soft-soldered originally.
 
Question had come up since there had been a few listener complaints in the fringes.
 
Anyhow, put in 4" strap to everything, including the ATU and one transmitter which had been grounded solely thru the AC line and the coax outer jacket to the ATU.  Put in a 4" strap ground ring aboutnthentower hase, and alother at the fencing about abot 10 feet from the tower base, and 4" straps to the tower base and to 3 lighting rod driven, and between the rings at 8 directions.
 
Putting in the rings and bonding the tower base increased the antenna current by about 5% for the same indicated transmitter power, and grounding the 1KW transmitter at its RF grounding point not only showed small arcs that sang during installation, but also increased the antenna current still more, another 3% perhaps, for the same transmitter input.
 
No big field reports in, but I know that if the ground systrem is still good all the way out, we ahve a more efficient and stable installation.  Next step will be to build a "sniffer" and check for integrity of all radials.  In the spring now!!  
 
And I was impressed again at how plenty of 4" strap from everything to everything can improve the efficiency of the system. especially old corroded ones using soft solder, and small wires.
 
And besides, it is fun for me to do the silver brazing!
 
Looey Munn
Roundup, Montana

Alan Alsobrook <radiotech at bellsouth.net> wrote:
I have an AM Combo here in Florida that had allowed pine trees to grow 
in the near field of the tower. Our plan was to remove the trees and 
replace the ground system. 
		
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