[Elecraft] EC! competition: Balanced auto ATU

Fri Feb 8 15:00:01 2002

One technique is to put the balun *ahead* of the ATU, and "float" the ATU.
That way, the balun always sees the same impedance, yet the output is
balanced.

Just wondering out loud:  How hard would it be to modify the existing KAT2
in this fashion?  It looks like the ground on the L-C board would have to be
isolated from both the chassis and the ground on the control board, and that
K17 and K18 would need to be re-wired.  Probably not a small task!

-----Original Message-----
From: Vic Rosenthal <[email protected]>
To: Elecraft <[email protected]>
Date: Friday, February 08, 2002 1:23 PM
Subject: Re: [Elecraft] EC! competition: Balanced auto ATU

>Ron D' Eau Claire wrote:
>>
>> The main interest in balanced feedlines for me and most ops I know is to
be
>> able to run very high SWR's on the feedline with multiband doublets,
G5RV's,
>> etc., and not suffer excessive losses. That means very high SWR's on the
>> feedline. High SWR's mean that the ATU has to deal with very large
impedance
>> transformations efficiently, and it has to be able to handle very high
>> voltages when it sees a high impedance at the feeder or very high
currents
>> when it sees a low impedance at the feeders.
>
>Absolutely right.
>
>Which means that a tuner with a built-in balun on the output side won't cut
it!
>
>73,
>Vic, K2VCO
>Fresno CA
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