On Wed, 2009-03-18 at 08:25 -0700, Jim Brown K9YC wrote:
> On Wed, 18 Mar 2009 08:38:46 -0600, Dr. Gerald N. Johnson wrote:
>
> >The higher power is saturating the core of the balun. One of the hazards
> >of tuning through the balun.
>
> Yes, very likely. There are several very different things called baluns. The
> one in antenna tuners is a transformer, so 100% of the transmitted power is
> in the core. Very likely to saturate with high power, heat, distortion.
>
> Another VERY different thing that is CALLED a balun is really a common mode
> choke. Put a bunch of ferrite cores around coax, or wind a bunch of turns of
> coax through one or more ferrite cores. Those are common mode chokes,
> commonly (wrongly) called "current baluns." But when done well (enough turns
> to have a high enough choking impedance), they work VERY well.
And if they don't have enough core cross section, they too can saturate.
But saturation is more difficult achieve with only one turn per core.
Their big claim to fame is that the allow the antenna to set the balance
where the transformer forces voltage balance.
>
> 73,
>
> Jim Brown K9YC
>
73, Jerry, K0CQ
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|