[TenTec] 4229 Tuner Balun Replacement?

[John Molenda]

Amen !  It drives the non technical Ham  like me crazy  .  John Molenda 
kb2huk
> You have hit on the heart of the reason why I am so opposed to the use
> of the word "balun" to describe a half dozen different things that are
> very different from each other, and why I use the words "common mode
> choke" when I mean a common mode choke. :)   In this respect, it's
> exactly like the word "ground" (or "earth" in British English).  The
> word "ground" is used to describe a half dozen different things
> (connections to the soil, connections between equipment for safety,
> circuit common, termination of cable shields, etc.), and that leads to
> MASSIVE misunderstandings about anything related to the uses of the word.
>
> This mis-use of words leads to a LOT of confusion about what things are
> and how they work.   The most generic definition I've seen of the word
> balun is that it is some sort of device that allows connection of a
> balanced circuit to an unbalanced circuit.  Some use the word to include
> the matching of impedances.
>
> An ordinary transformer allows the connection of balanced and unbalanced
> circuits to each other, and, depending on the turns ratio, can also do
> some impedance transformation.
>
> Transmission line transformers of various sorts are also called baluns,
> and many of those variations are VERY different from each other.  Some
> use transformer action with windings coupled via a ferrite core, while
> others use windings configured so that the core sees only common mode
> current. Some use cores that are predominantly inductive with very low
> loss,  while others use cores that cause the choke to function
> essentially as a low Q parallel resonant circuit.  The design,
> effectiveness, losses, dissipation, and voltage stresses, are very
> different from one type of so- called "balun" to another.
>
> Another completely different so-called balun is a half wave length of
> transmission line that allows the two sides of  a tee-matched driven
> element to be driven by coax. The coax feedline connects directly to one
> side of an antenna and the center of the driven element, the half wave
> of line connects from that point to the other side of the antenna and
> the driven element so that, at resonance, the opposing sides of the
> element are driven 180 degrees out of phase so that their total fields add.
>
> If you live in the video world, you can buy a piece of electronics that
> allows the 75 ohm video output stage to drive unshielded twisted pair
> (like CAT5).  That box is also called a balun by those who sell and use it.
>
> 73, Jim K9YC
>
> On 11/14/2010 5:49 PM, Richards wrote:
>> Apropos our previous discussion of "choke baluns"...
>>
>> I believe the locution "choke balun" is often used to refer to various
>> forms of chokes - sometimes made of ferrite beads and sometimes made
>> of round ferrite toroids.  I presume you are talking about the more
>> traditional and more robust "balun" (transformer) designs which employ
>> large, round ferrite toroids - and not the so called  "choke baluns"
>> comprised of a series of ferrite beads along a stretch of coax.
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec