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

[Don Wilhelm]

Andrew,

The BL2 on the output of the tuner may not be the total answer.  The 
conditions and situations are too numerous to address.  I would suggest 
some study into antennas and transmission lines before assuming that 
"anything will work" - because it is not true that "anything will work".
The one thing I can say is that if you can make an antenna take a load, 
that power will be radiated.  Beyond that statement, I take no 
responsibility for the specifics, it all depends on the particular 
installation.

As one "for instance", attempting to feed the end of a 1/2 wavelength 
wire will likely result in failure.  The KAT3 is not designed to work 
into a quite high impedance.

73.
Don W3FPR

On 9/28/2012 7:06 PM, Andrew Moore 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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