balun question

[Bill Coleman]

On 3/10/02 2:43 PM, rayfri at rayfri at NETWORLD.COM wrote:

>what determines how much power a balun coil can handle

Depends on the type of balun. Those using ferrite or powdered iron cores
are likely limited by the losses in the cores. (These losses cause
heating, which tends to increase losses -- at some point, the losses
"take off" and heat the core to the curie temperature)

Air-wound baluns are often limited by conductor size and the currents
therein. Certain coils might be limited by peak voltage breakdown.

>and what might
>happen if that power level is exceeded???

Depends on what the limiting factor is. From the causes listed above, you
could see core heating to destruction, melting of conductors or
insulation, or arcing.

>here's the situation .....
>I have a Heathkit B-1 balun, which we heath lovers know uses air wound
>coils.
>The B-1 is rated by Heath at about 200 watts power handling
>capability...
>so, what determines that that is its power handling capability, and what
>might
>happen if I were to put 500 or 600 watts into it?

You can make a lot better balun choices than the old Heathkit B-1. I
believe this is an old voltage balun. You'll achieve better balance by
using a current (choke) balun.



Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901

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