[TenTec] which balun?

[Rick - DJ0IP / NJ0IP]

James,

Good news, bad news on your suggestion to use two separate baluns for the
job.

The good news is, your suggestion to use two baluns is a great idea.
The bad news is, even though you probably concluded this on your own, it is
not a new concept.

In fact it was described at great lengths in the Sep/Oct 2005 issue of QEX
magazine.  The article entitled "A Better Antenna-Tuner Balun" was written
by Andrew Roos, ZS1AN.
http://www.arrl.org/files/file/Technology/tis/info/pdf/QEX_Sep_2005_p29-34.p
df 
or:
http://f1frv.free.fr/main3c_Baluns_fichiers/A_Better_Antenna_Balun_ZS1AN.pdf


In this article, Andrew introduces the idea of a Hybrid Balun.
However, in reading his conclusion, he says it maintains a good balance and
good rejection of common mode current across a wide range of high impedance.


I don't know what will happen when using it to match a dipole with a 10 Ohm
impedance.  People may be asking why anyone would do that, but it is a very
realistic low-band antenna for a city-dweller here in Europe.  

73
Rick, DJ0IP

____________________________________________________


	Given the problems winding everything on
	a single core - and recognizing using two
	toroids as a single core is STILL USING
	just ONE CORE...

	Would one be be better off having two separate
	devices,  i.e., one to act as a 4:1 impedance
	transformer and another to act as a common
	mode choke?

	If so, might we go one step further and suggest
	it is better to just wind them separately and
	maybe even put a little space between them to
	minimize stray capacitance, inductance, etc?
	Maybe put them in different NEMA boxes, even?

	It seems that would give each device more "room"
	to do its separate job independently of the other
	one.   If that is the case, the only down side
	would be the additional cost of another or a
	larger NEMA box, and maybe a couple extra
	connectors.


Any traction?

===================  K8JHR ===================
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