[Elecraft] High power tuner

[David Gilbert]

You misunderstand me.  I never said that being published by the ARRL 
made it a good design, and in fact I think that the ARRL has a horrible 
track record for technical integrity on many of their published articles 
(particularly those in QST).  Much of what we read there is just flat 
out wrong.   I merely pointed out that Alpha seemed to think that being 
published in ARRL gave the tuner design credibility ... an unwarranted 
association from my perspective.

Dave   AB7E



On 11/26/2011 8:44 PM, Don Wilhelm wrote:
> Just because it was published by the ARRL does not make it a good
> design, although it might help to sell a few.
>
> Zack Lau published a QRP version of that tuner some years back and later
> retracted it, and it has not been mentioned much since, but Dean Straw
> published his high power version of about the same design and that seems
> to be the "best thing since sliced bread" despite counterclaims by noted
> authorities on balun and RF designs - W8JI, W7El and others.  Bottom
> line, it just does not work well, although there will be many who will
> say that "Alpha makes good stuff", that still makes it a stretch of the
> laws of physics - using an unbalanced network "floating" (although not
> really isolated from a common reference (ground)) will still not make
> everything balanced.
>
> I know there are those who will claim that an off center fed dipole has
> a balanced feedpoint, but I am not convinced.  I put the "balun at the
> input" tuners in the same category.  Take a balanced signal (output of a
> balun) and feed it through an unbalanced network, and claim that the
> output of that unbalanced network is balanced just does not make much
> sense to me.  Maybe with ideal components it *might* be possible, but if
> one would plot the reactance and phase delay around that unbalanced
> network using good scientific methods, it would become obvious that the
> output would not be of equal and opposite currents with 180 degrees
> phase difference.  If the schematic does not look balanced, it is not
> really balanced.  Follow the leading current and lagging current around
> the circuit to convince yourself.
>
> 73,
> Don W3FPR
>
> On 11/26/2011 10:10 PM, David Gilbert wrote:
>> If I remember correctly, the announcement for the Alpha tuner even
>> stated that they "drew heavily" (or words to that effect) from the ARRL
>> Antenna Book for the design.
>>
>> 73,
>> Dave   AB7E
>>
>>
>>
>> On 11/26/2011 6:37 PM, Paul Christensen wrote:
>>>> I was surprised to see this from Alpha, whom I would have expected to know
>>>> better.
>>> The identical design (less automated functions) can seen in recent issues of
>>> the ARRL Antenna Book  For example, see 20th Ed., pp. 25/15 - 25/19 and
>>> titled "High-Power ARRL Antenna Tuner for Balanced or Unbalanced Lines."
>>> Even output C is the same at 800 pF max.
>>>
>>> Paul, W9AC
>>>
>>> __
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