[Elecraft] KAT3 Automatic Antenna Tuner

[Guy Olinger K2AV]

I'd have to agree with Don on this one.  Fully automatic (auto-auto)
would drive me up a wall.  There would have to be a semi-automatic
mode, something done to keep the radio from tuning, except when I
wanted it to.

For those who want the business of tuning low power into a relatively
low SWR into an amp versus tuning to a high SWR taken care of
automatically in a K3, I would submit that the box that really needs
the change is the AMP, NOT the K3.  Why shouldn't amps with auto
tuners on the output make that available in the bypass?   Then one
autotuner serves both purposes transparently.

If one has an amp without an autotuner, what's the fuss?  One has to
manually change the high power tuner with QSY anyway (have to remember
to move one's hands and tune) and dropping the K3 tuner from the
string to drive the amp is A SINGLE BUTTON PUSH when you kick in the
amp. In my case I do them both at the same time with both hands.  It's
a habit.

Kicking the amp in or out is manual.  Why should this issue get dumped
on anybody's brand of transciever?

As to the ideal that other rigs doing something is why a K3 should do
it, there is a long list of things in common from YaeComwood that I'm
happy to be without.  Just because it was done in a Japanese box
wouldn't buy a cup of coffee around here.  It's on a case by case
basis. Start with key clicks and front ends that go mush in the night.

Part of the consideration on what to do in an equipment design has to
do with what the public has already accepted in a line of products (K3
continues on the K2 tuner). But more than that at some point
additional features become prohibitive and time/expense has to be
contained.  IF auto-auto could be done in firmware, the problem as
always in the software industry is 200 hours of ideas for 40 hours of
programmer time.  And seemingly nobody that hasn't done hardware
control coding themselves understands how difficult and pernicious
that kind of code is.

Again, if Wayne could do auto-auto-tuning, there'd have to be an
option to turn it off, which I would do. There would also be the issue
of setting the SWR threshold. Some would want it to kick in at 1.2:1.
Others would set it to 5 watts of fold-back.

No flame intended here, but I'm not with you on this one.

73, Guy

On Wed, Mar 24, 2010 at 10:07 AM, Don Wilhelm <w3fpr at embarqmail.com> wrote:
> Robby,
>
> Since the KAT3 can be configured with one antenna port in bypass and the
> other for normal tuning, why not put the amp on ANT2.  That should make
> things easier when switching between barefoot and the amp.
>
> I know that does not solve the problem of switching antennas on ANT1.
>
> BTW, the K3 does protect itself by reducing power if a high SWR is detected.
>
> 73,
> Don W3FPR
>
> Robby.VY2SS wrote:
>> The problem with automatic selection of memorized settings is it stops being
>> useful when you change to an  antenna that has different charactaristics. Or
>> you turn on an amplifier that presents a different load than your antenna.
>> In these cases your memory settings are all working against you.
>>
>> If I always used the same set of antennas and always did or did not use an
>> amplifier I would not be having these problems. At least now I know that to
>> be safe I need to press that button before every transmission after an
>> antenna or power level change. I have a hard time accepting that as
>> automatic but it may well depend on an individual's definition of the word.
>>
>> I would prefer to have my tuner ensure that my finals are not seeing a high
>> SWR.
>>
>>
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