Because it stores energy during the portion of the cycle that the tube is cut
off.
Vic K2VCO /4X6GP
> On Jan 13, 2015, at 6:59 AM, Fuqua, Bill L <wlfuqu00@uky.edu> wrote:
>
> 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
>>
>>
>> _______________________________________________
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>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
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