[TowerTalk] guys, insulators, etc

[T A RUSSELL]

On Sat, 18 Jul 1998 08:23:42 EDT Mmoon3@aol.com writes:
>
>I have a copy of the Antenna Handbook, but would like to know current 
>trends
>in non-resonant guy lengths.  My guys will be about 55' long.  Should 
>I have
>about 3' at the top, then an insulator, then 14', then 14', then 27', 
>then
>insulator, then anchor?  Is this safe for 14, 21, 28 MHz?

	14 ft is too close to a half-wave on 28 MHz.  I use 12 ft,
	insulator-to-insulator, 2 each, followed by 27 ft. lengths.
	With guy grips, it is best to cut the lengths 1 ft shorter. 
	The first insulator needs to be as close as possible
	to the tower (3 to 4 ft.)  as you are planning.   N4KG
>
>Does everyone use 504 insulators, or 502?  I can get 504's from my 
>local electrical supplier for only $4.55 each.   I will be using 1/4"
guy 
>wire. 

	The large (fist size) insulators should be used with 1/4 inch
	guy wire.
	 
>Should I use "genuine" Rohn 1/4CCF clamps (forged, hot dipped) or are 
>the malleable ones OK?

	AARGH!  Most people have gone to using "guy grips",
	actually called "dead-end's"  in the industry.  They
	can be purchased individually from Texas Towers or
	boxes of 50 (for 1/4 inch) or 100 (for 3/16 inch) from
	Preformed Line Products Company in Cleveland, OH.
	I have seen two towers fall over where guys pulled
	through cable clamps that have worked loose.  In both
	cases, I believe there were only two clamps installed
	and the cable was not "served" as shown in the Rohn
	catalog.  Serving 1/4 inch cable is a royal pain.  Cable
	clamps can work loose with time and need to be 
	inspected / retightened on an annual basis.  Go back
	and forth between the nuts as the first one will loosen
	when the second is tightened.  Just this year at Field Day
	I found a loose clamp and the guy informed me he had
	tightened them with a wrench.  Obviously he did not go
	back to the first nut.  If you insist on using clamps, be 
	sure to use good quality galvanized clamps, 3 each.

	Guy grips are a snap and cost effective.  My guy grips 
	and 1/4 inch cable held up two 70 ft trees which fell on 
	them following a small tornado.   Enough said?   N4KG	

>
>Thanks, 73,
>Mark N3AVA/0
>

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