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Re: [TowerTalk] two benefits of postings on Re: Resonance is overrated

To: "Gary Schafer" <garyschafer@comcast.net>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] two benefits of postings on Re: Resonance is overrated
From: "Al Williams" <alwilliams@olywa.net>
Date: Mon, 10 Aug 2009 07:16:09 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Yes, I agree that the original poster was probably referring to the end 
result.  That is why I mentioned "misstated" at both the beginning and end 
of my posting.

However unless usage of terms has changed since I learned them or there is a 
big segment of the population that refers to the "end result" as having 
reactance then you are also making a mistatement i.e.  using terminology 
that can be misleading and confusing.

"Negative and Positive" reactance is a misnomer as it really is a shorthand 
way of saying
there is a phase shift between the voltage and current.  I have never read 
how the term
reactance was applied but I suspect that it refers to how capacitance or 
inductance reacts to an applied alternating voltage.

Of course the "end result" of a circuit containing both capacitance and 
inductance could be thought of as reacting to an alternating voltage. 
However someone invented the term
impedance for this "reacting" result.  I presume the purpose of this change 
in terminology was to lessen confusion, provide better communication, and 
understanding of the circuit.

That was the purpose of my posting.

k7puc


----- Original Message ----- 
From: "Gary Schafer" <garyschafer@comcast.net>
To: "'Al Williams'" <radioman007@comcast.net>; <towertalk@contesting.com>
Sent: Sunday, August 09, 2009 9:12 PM
Subject: Re: [TowerTalk] two benefits of postings on Re: Resonance is 
overrated


>I think that he was referring to the end result of the total circuit. It 
>may
> have capacitive and inductive components in it but the capacitive ones 
> will
> exhibit a negative reactance and the inductive a positive reactance.
> The resulting impedance will be either resistive, if resonant, or it will 
> be
> resistive with a capacitive reactance or resistive with an inductive
> reactance. It can not have inductive and capacitive reactance together in
> the end result.
>
> 73
> Gary K4FMX
>
>> -----Original Message-----
>> From: towertalk-bounces@contesting.com [mailto:towertalk-
>> bounces@contesting.com] On Behalf Of Al Williams
>> Sent: Sunday, August 09, 2009 5:01 PM
>> To: towertalk@contesting.com
>> Subject: [TowerTalk] two benefits of postings on Re: Resonance is over
>> rated
>>
>> One benefit of so many postings on this subject is that raises concepts 
>> or
>> different ways
>> of analying the "problem".
>>
>> A second benefit is that some postings causes us (me) to review my
>> understanding of things that I learned long ago--in this case over 50
>> years!
>>
>> The following posting states something that is not only incorrect but the
>> truth is exactly the opposite. Actually it was probably mistated.  For
>> those
>> less trained, here is the correction:
>>
>> 1. All circuits have both a capacitive and an inductive reactance at the
>> same time.  All circuits will have some lead length
>> which will result in an inductance, no matter how short the lead.  The
>> inductive reactance xl will be  2piFL accordingly.
>> Similarly all circuits will have some spacing between components or leads
>> resulting in capacitance.  The capacitive
>> reactance will be 1/2piFL.  These two reactances can be mathematically
>> combined serially or parallel.  I forget if it was
>> Norton, Thevinin, etc. who established the series and parallel formulas.
>> There will also be a resistance which must also be included
>> (or ignored). The resultant equation is (r1+xl)(r2+xc)/r 1+ xl + r2 + xc)
>> for a parallel combination.
>>
>> 2. The units for the resultant equation is called impedance-- not
>> reactance?
>>
>> 3. A minor mistatement probably?
>>
>> ----- Original Message -----
>> From: "W3YY" <w3yy@cox.net>
>> To: <towertalk@contesting.com>
>> Sent: Friday, August 07, 2009 7:44 PM
>> Subject: Re: [TowerTalk] Resonance is over rated
>>
>>
>> >
>> > Something either has capacitive or inductive reactance, both not both 
>> > at
>> > the
>> > same time.
>>
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