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Re: [Amps] The genius of ham radio

To: wlfuqu00@uky.edu, k8ri@rogerhalstead.com, amps@contesting.com
Subject: Re: [Amps] The genius of ham radio
From: Gerald Williamson via Amps <amps@contesting.com>
Reply-to: TexasRF@aol.com
Date: Tue, 13 Jan 2015 10:28:20 -0500
List-post: <amps@contesting.com">mailto:amps@contesting.com>
Wouldn't a tuned circuit be most any LC adjusted for resonance as in  
receivers and other low level applications. And a tank circuit is primarily for 
 
a higher power transmitter application?
 
Gerald K5GW
 
 
 
In a message dated 1/12/2015 8:59:21 P.M. Pacific Standard Time,  
wlfuqu00@uky.edu writes:

As to a question I asked earlier.
Why is a tuned circuit sometimes called a  tank circuit?
This is a term that goes back more than 100 years. 
Any  guesses?
73
Bill  wa4lav
________________________________________
From: Amps  [amps-bounces@contesting.com] on behalf of Roger (K8RI)  
[k8ri@rogerhalstead.com]
Sent: Monday, January 12, 2015 11:40 PM
To:  amps@contesting.com
Subject: Re: [Amps] The genius of ham  radio

Aren't proven theories then referred to as physical  laws?

73

Roger (K8RI)


On 1/12/2015 12:58 PM, Jim  Brown wrote:
> On Mon,1/12/2015 8:36 AM, greg greene  wrote:
>>   the difference between
>> theory and  practice - is the difference between theory and practice'
>>  what
>> he meant by that was that theory is the guide - practice is  result, when
>> the two don't match - review both.  Theory is  never 100% - that is
>> why it
>> is theory
>
>  The word "theory" here is misapplied.  Somehow, we in the radio  world,
> long before most of us became hams, divided the FCC exam into  a
> written exam, which was CALLED "theory" and the CW exam. What  that
> exam covered (and still does) is a combination radio Rules,  operation,
> and fundamental physical principles. NOT unproven  "theory."
>
> Human understanding of how things work has been well  known for a LONG
> time. Nearly 100 years ago, Bell Labs published the  concept of the use
> of feedback to reduce distortion in amplifiers with  a corresponding
> reduction in gain. The fundamentals of   transmission lines and
> antennas are also that old. Before that work  was proven by disciplined
> experiment, it could reasonably be called  "theory," even though it was
> clearly proven by the  math.
>
>> - the more we observe the results of practice - the  closer we get
>> to redefining the theory, and then the closer we get  to refining the
>> practice.
>
> Jim Garland addressed  this quite well in his post. REAL components are
> not ideal --  inductors have series resistance and parallel
> capacitance. When we  look at a circuit diagram that shows an inductor
> and ignore that fact,  WE have failed to apply fundamental principles.
> This is not a failure  of "theory" nor those principles. Likewise, when
> we look at a resistor  and fail to see it's self inductance (and even
> parallel capacitance),  and look at a capacitor failing to see it's
> series and parallel  resistances and series inductance, it is WE who
> have failed, NOT  "theory" -- those fundamental principles. And, of
> course, active  components -- tubes, transistors, and diodes also have
>  strays.
>
> I was trained as an EE, and spent much of my life in  the field of
> "engineering." Real engineers are trained to understand  the whole
> picture, the strays, the costs of eliminating or reducing  them, and
> when to stop with "good enough." We don't need, nor can we  afford
> "ideal" -- we must work with the real estate that our home sits  on,
> with the sky hooks that are on it, and cash in our bank account  to
> build antennas that "work."
>
> Inside our radios and  amplifiers, we must look for and understand what
> Henry Ott calls "the  invisible schematic hiding behind the 'ground'
> symbol," as well as the  complete schematic that includes those stray
> Rs, Ls, and Cs. Failure  to do that is OUR failure, not "theory," those
> fundamental  principles.
>
> Understanding HOW antennas work allows us to  achieve a better result
> faster. Sure, we could build a dipole, operate  it at various heights
> in increments of 5 ft, and use a drone with  instruments attached take
> a lot of measured data to see it's  directional pattern, both vertical
> and horizontal. Bring a very fat  wallet to this process. OR, build a
> model of that antenna in NEC and  have it compute the 3D pattern at
> various heights in increments of 5  ft. I've done that in a day or so.
> I now KNOW, in dB, the value of 10  ft of additional height on 80, 40,
> and 20M. That work, BTW, is on my  website.
>
>  http://k9yc.com/VertOrHorizontal-Slides.pdf
>
> 73, Jim  K9YC
>
>
>  _______________________________________________
> Amps mailing  list
> Amps@contesting.com
>  http://lists.contesting.com/mailman/listinfo/amps
>


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