[Elecraft] K2, KAT2 and displaced choke balun feed

[Don Wilhelm]

Dick,

Warning, a bit of theory talk follows:

I believe your post combined two different aspects of tuners.  Matching 
range limitations are a fact of life with any tuner design whether 
auto-tuner or manual and whether a balanced tuner or an unbalanced tuner.
In my attic I do have an old homebrew, link coupled, tapped plug-in coil 
tuner that I can use to match most any load that I can through at it - 
it has straps to configure it for series tuning if the impedence is low 
and when configured for parallel tuning, will match a very high 
impedance.  BUT, it is not very good at bandswitching, and if I change 
the antenna, I have to set things up again.  Those were the 'good old 
days' and it worked very well when I was confined to one or two antennas.

As far as balance from a balun output goes, theoretically the output 
should be very well balanced if the balun is a proper balun.  If you do 
not have good balance from a balun, I believe you really should be 
asking how your installation differs substantially from the theoretical 
model of a balun and solve the problem at its source.

With a good balun at the output of a good unbalanced autotuner, the 
balance *should* be perfect.  The task of finding out why it may not be 
perfect in any one installation may indeed be more difficult than giving 
up and simply using a modern balanced tuner even with  the drawbacks of 
any of the currently available balanced tuners.

For myself, I choose the easy solution for portable operation - the KAT2 
followed by a balun works great for me, and at home I have all resonant 
antennas so a tuner is not required except for a minor 'touch-up' on the 
high end of 75 meters (and I don't operate there very often), so an 
unbalanced tuner works fine for my applications.

73,
Don W3FPR

Lamb, Dick & Judy wrote:
> I had exactly the same experience as Roel and reached the same 
> conclusions.  I agree that a commercial BALANCED autotuner would be 
> the best solution for an all-band dipole, if there were such a thing.
>
> snip...