Brainteaser
 

K7ITM wrote:

It's somewhat comforting that it's just as you'd expect from power
delivered versus time. It's an illustration of something I believe Ian
White was trying to get across in another thread: there are commonly
multiple ways to analyze a problem, and if they agree, you MAY have the
right answer. If they disagree, you have at least as many wrong
answers as the number of disagreements (or perhaps the disagreements
only seem to be disagreements).


What I said was that there are commonly multiple methods to analyse the
same problem, but that all correct methods MUST agree, because they are
only different views of the same physical reality.

(I think that amounts to the same as you said above, Tom.)



--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Brainteaser
 

Ian White GM3SEK wrote:
What I said was that there are commonly multiple methods to analyse the
same problem, but that all correct methods MUST agree, because they are
only different views of the same physical reality.

That attitude is certainly an improvement from the earlier
labeling of an alternate valid analysis as "Gobbledygook".
--
73, Cecil http://www.qsl.net/w5dxp

Brainteaser
 

Cecil Moore wrote:
Ian White GM3SEK wrote:
What I said was that there are commonly multiple methods to analyse
the same problem, but that all correct methods MUST agree, because
they are only different views of the same physical reality.

That attitude is certainly an improvement from the earlier
labeling of an alternate valid analysis as "Gobbledygook".

"Improvement" implies a change; but I have always held the same view as
quoted above.

It is one of the main reasons why I remain sceptical about your
theories. Where they ought to be agreeing with other analyses of the
same problem, they don't.


Also, "gobbledygook" is not a word I use... it's one of yours, I
believe.


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Brainteaser
 

On 26 May 2006 15:50:07 -0700, "K7ITM" wrote:

To heck with the red wine...think I'll have another shot or two of the
Scapa single-malt this evening.

Hi Tom,

Is the Scapa flowing?

73's
Richard Clark, KB7QHC

Brainteaser
 

Ian White GM3SEK wrote:
It is one of the main reasons why I remain sceptical about your
theories. Where they ought to be agreeing with other analyses of the
same problem, they don't.

No chance the "other analyses" could be wrong? Could you
please give me an example of what you are talking about?

Also, "gobbledygook" is not a word I use... it's one of yours, I believe.

I didn't say you used it, Ian, but you didn't object when it
was used.
--
73, Cecil http://www.qsl.net/w5dxp

Brainteaser
 

Well, after communing this evening with some hard cherry wood from my
back yard that's going to become part of a loom, I decided to go with
the Ledaig instead.

Cheers,
Tom

Brainteaser
 

Ian wrote, "(I think that amounts to the same as you said above, Tom.)"

Well, I hope so...I'd certainly not intentionally misstate it. I do
think your way of putting it is a bit more positive than mine, though.

Cheers,
Tom

Brainteaser
 

In a previous posting, I noted that for the 100 ohm line driven by
200*sqrt(2) volts DC through 100 ohms, there are two load resistors
that dissipate 100 watts: 100*(3 +/- sqrt(8) ) ohms. Continuing the
observation about energy stored in electric versus energy stored in
magnetic fields, for the low resistance, the steady state load and line
voltage is low and the current is high; for the high resistance, the
steady state voltage is high and the current is low. In the first
case, 8.5786 joules is stored in the electric field and 291.42 in the
magnetic; in the second those are reversed and 291.42 are stored in the
electric and 8.5786 in the magnetic. The ratio of the two energies is
exactly the same as the ratio of the load resistances.

In our lossless line, if the excitation is AC and steady-state has been
reached, then the total energy stored per unit length varies as a
function of time and distance in a somewhat complex manner. The ratio
of electric to magnetic varies along the length of the line and as a
function of time, with extremes being in a ratio equal to the square of
the SWR, occuring of course at voltage and current maxima, spaced 1/4
wave apart, alternating down the line.

I'm not sure that those observations will be any use to anyone, but
maybe they are of academic interest. Who knows what I might come up
with after some Glenmorangie.

Cheers,
Tom

Brainteaser
 

Cecil Moore wrote:
Jim Kelley wrote:

One should also carefully consider the more interesting variation of
the problem: an open transmission line. In the steady state we have
100 watts forward, 100 watts reflected, 200 Joules in the line, and 0
watts being sourced by the generator. :-)


Yes, but the 200 joules in the line was previously sourced
by the generator during the transient state. It's hard to
sweep 200 joules under the reflected power rug.

So is this your proof that Joules of
energy are likewise reflected from
antireflective surfaces?

ac6xg

Brainteaser
 

Cecil Moore wrote:

Jim Kelley wrote:

One should also carefully consider the more interesting variation of
the problem: an open transmission line. In the steady state we have
100 watts forward, 100 watts reflected, 200 Joules in the line, and 0
watts being sourced by the generator. :-)


Expanding on my earlier response - For the first two seconds,
the source doesn't know it is looking into an open transmission
line so a 100 watt source would faithfully output 200 joules
into a one second long open circuit transmission line. That
200 joules cannot be destroyed. Is it mere coincidence that
the forward and reflected waves are 100 joules/sec*(one second),
exactly equal to the 200 joules supplied by the source?

But you're missing, or trying to
circumvent, the most interesting aspect
of the problem. It's the one which
highlights the very core of our
disagreement. The energy stored in the
line, remains stored in the line as long
as steady state is maintained without a
single Joule of additional energy moving
into or out of the line. To me, this
illustrates clearly how the fields at
the impedance interfaces of a matching
transformer can be maintained without
requiring multiple rereflections of
energy. I'm hoping some day you'll see
it too.

73, ac6xg