[TowerTalk] Avoiding Grounded 1/4 Wave Guy Sections

[AD7L@aol.com]

Hello All -

Per the ARRL Antenna Book and Handbook, we know what ungrounded lengths of 
guy wire to avoid.  Also, GROUNDED wires will exhibit resonance at odd 
multiples of a quarter wavelength.  

My question is how important is it to avoid these resonant lengths of 
grounded wires, where the grounded wire is the last section of your otherwise 
insulator divided guy.  The ground is to the anchor, which, for a typical 70' 
tower, is 56 feet away from the tower itself.  The wire is in a different 
plane than the yagi up top.  If I wanted to plant a vertical next to a guy 
wire, I could easily see the negative impact of having a resonant wire 
nearby.  But for a yagi which is 40 feet or so away from the highest point of 
this grounded wire, how big is the impact?

My particular scenario is for a tower dedicated to the WARC bands (all 
three), and the last section of guy, which is grounded, is about 30' long.  
If the actual length is a bit short, there is a resonance on 12M at 28.2', 
and if the length is long, there is a 17M resonance at 38.8'.

I hate to break the guys up to much more; the cost of insulators and big 
grips will have me on an extended diet of beans and weenies.

73,

Ron  AD7L
Hillsboro, Oregon



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