[TowerTalk] Coaxial Choke Baluns

[T A RUSSELL]

On Mon, 2 Aug 1999 12:00:34 EDT N6CW@aol.com writes:
>Tom,
>
>Thanks for the info on buluns. A quick couple of questions. While it 
>is easy to wind a balun on a 4 or 6 inch form, what do we do with it 
>once we have it? 

	I wound a choke for my 2L40 on a 3 Liter Coke bottle
	and suspended in below the boom using tie-wraps
	and tape.   N4KG

>Would it degrade the balun by mounting the balun with the antenna mast 
>or boom running through it? I suspect not. 

	Unfortunately, it will degrade performance.  N4KG 	

This would allow a way to support the balun and not have a big blob 
hanging off the antenna. 

	Understand.  Mechanically good but electrically bad.  N4KG

Or how about if  you had a 4 inch boom, could you just wind the 
balun around it or even hang it through a 2 inch boom?

	The closer the choke is to the metal, the more it
	couples (capacitively) and the greater the degradation.
	N4KG

 Or since I have a tubular tower with a 4 inch square top section 
could I just  wind it around that section. 

	This would be better than winding it on a 4 inch metal
	cylinder, especially if you spaced it away from the tower.   
	But still not at good as if it were not wound around the tower.
	N4KG

Also do you have info for a 80 meter dipole? 24 turns on 4 inch tube?

	Dunno...I had a problem with an 80M dipole being detuned
	after I installed a 3L20 at the mid point of the 130 ft tower.
	Apparently there was an 80M resonance between the top
	and bottom beams which were separated by 70 ft and end
	loaded by the beams.

	You might want to go to a larger tube to reduce the number
	of turns needed.  Believe there is some 6 inch PVC or other
	type of tube available.      N4KG

	
>Just curious.
>
>Terry/N6CW 


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