[Elecraft] Is a K3 ATU with balanced outputs possible?

[N5GE]

Put the balun outside and bring the coax into the shack.

I am feeding a large NVIS loop with my K3.  The loop is fed with 450
ohm window line which connects to a 4:1 balun under the eve of the
roof before it enters the shack.  The K3 is connected to the balun
with 50 ohm coax. My K3 tuner will match the load from 160 to 10
meters.  When running the KPA500 I use a large 2000W tuner.


Aword of caution:  Make sure your window/ladder line does not touch
the house anywhere.  It could start a fire.

Amateur Radio Operator N5GE
ARRL Lifetime Member
QCWA Lifetime Member

On Fri, 28 Sep 2012 19:06:36 -0400, Andrew Moore
<andrew.nv1b at gmail.com> wrote:

>Great; thank you for the trivia, very helpful. I figured it had already
>been considered and that there was a good reason for the current
>configuration.
>
>The BL2 following the KAT3 was exactly one option I was considering. I've
>read about several cases in which ops had success, but read others in which
>the balun was heating perhaps due to excessive reactance on the antenna
>side. Reactance is likely dependent on the frequency/band and several
>factors in the antenna system which could explain the mixed results.
>
>I think I will try this approach and enjoy the experimenting.
>
>All: Not looking to turn this in to an OT antenna theory thread, but if you
>have specific experience with this configuration, I'd like to hear (KAT3 to
>BL2 to ladder to simple dipole).
>
>Thanks,
>--Andrew, NV1B
>maineware.net
>..
>
>
>On Fri, Sep 28, 2012 at 6:43 PM, Don Wilhelm <w3fpr at embarqmail.com> wrote:
>
>> Andrew,
>>
>> A bit of 'trivia' first:
>> That was "supposed" to be a solution in the KAT500 tuner.  The initial
>> design put the balun on the input of the tuner, and attempted to "float"
>> the rest of the tuner while trying to maintain balance.
>>
>> There were problems with maintaining balance through the rest of the
>> tuner, while studies indicated there was no efficiency difference between
>> the balun at the input vs. the balun at the output, so the design was
>> changed to an unbalanced design driving (if required or desired) a balun at
>> the output of the tuner.
>>
>> "trivia off":
>>
>> So more specific to your question, a balanced output from the K3 KAT3 can
>> easily be obtained by using an Elecraft BL2 on the output side of the KAT3.
>>
>>
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