Mismatched Zo Connectors
 

Richard Clark wrote:
Cecil Moore wrote:
I also haven't denied that 100 angels cannot dance on
the head of a pin for exactly the same reasons.

So, you have a reason to agree that 100 Joules is the right answer?

As the problem was stated, I have NO reason to include 100
joules in the set of correct answers. I also have NO reason
to exclude 100 joules from the set of correct answers.

If Jim had specified that the forward power and reflected
power in the one-second long lossless stub was 50 watts
each during steady-state, then we could conclude that
there is 100 joules in the feedline.
--
73, Cecil http://www.qsl.net/w5dxp

Mismatched Zo Connectors
 

Cecil Moore wrote:
If you change the source to a Thevenin equivalent 141.42V
and 50 ohm source impedance and specify Z=50 ohms feedline
impedance then the problem becomes solvable.

Going with this configuration which is similar to the 1/2
WL stub suggested by W7EL in his Food For Thought #1:

SW
Source nc c Pfor=100W-- --Pref=100W
141.4V---o---o---one second long lossless 50 ohm stub--open
50 ohm
o---/\/\/\/\/\--Gnd
no 50 ohms

For the first two seconds after power up, the Thevenin
source delivers 200 joules into the stub while dissipating
200 joules as heat in the source resistance. Those 200
joules of energy in the stub must be conserved.

During steady-state, assuming the stub is an exact integral
number of wavelengths, the source will see an open circuit
and be delivering zero power. A wattmeter calibrated for
50 ohms will read 100 watts forward power and 100 watts
reflected power during steady-state.

After steady-state is reached, we throw the switch and connect
the stub to a 50 ohm dummy load. 100 watts will be supplied
to the dummy load for two seconds for a total of 200 joules.

Who was it who said that reflected power cannot be
recovered? (Food For Thought #1 on www.eznec.com).
--
73, Cecil http://www.qsl.net/w5dxp

Mismatched Zo Connectors
 

On Sat, 02 Sep 2006 13:15:02 GMT, Cecil Moore
wrote:

As the problem was stated, I have NO reason to
.... blah, blah, blah, blah

What a tedius excuse.

My answer stands, contradicted but without ANY correction. There's no
challenge in saying "'t'ain't so," or offering mea culpas, regrets,
plea bargains, or reams of Xerox copies of plate tectonics as applied
to transmission line theory.

What a boring strip-tease....

Mismatched Zo Connectors
 

Richard Clark wrote:
My answer stands, contradicted but without ANY correction.

I have corrected it in another posting. With a 50
ohm, 141.4V Thevenin source, the answer is 200 joules,
not your 100 joules. It takes two seconds for a one
second long lossless feedline to "fill up" with energy.
--
73, Cecil http://www.qsl.net/w5dxp

Mismatched Zo Connectors
 

On Sat, 02 Sep 2006 18:08:52 GMT, Cecil Moore
wrote:

I have corrected it in another posting...

Blah, blah, blah, tailored of course to a different problem. SOS

Hi All,

I saw Albert Brooks movie "Looking for Comedy in the Muslim World"
last night that had a routine by him that reminds me of this
boot-shuffling, toe-scrubbing side-step:

Brooks (to an audience of mixed Muslims, Hindus, Sikhs....):
"We are going to investigate the humor of improvisation and I need you
to give me a nationality"

"German!"

"OK, German. Now how about a occupation?"

"Farmer!"

"OK, a German Farmer. What does he raise?"

"Turnips!"

"Is he married?"

"Yes, with 5 children!"

"OK, is he rich or poor?"

"POOR!"

"OK, a poor German Farmer, married with 5 kids who raises Turnips.
That's great, we are going to have a lot of fun with this. (starting
to rummage up a routine, and then changing his mind) No, I don't like
him being German. We are going to make him Chinese, but Chinese don't
raise beets, they raise rice and they are doing pretty good, so he's
not poor.

"So, we have a middle class Chinese rice farmer with 5 kids - NO! I
read somewhere they have a population limit, and I don't want him
married. Let's make him divorced with 1 kid.

"No - raising rice is such a stereotype, so let's make him a bus
driver.

"OK, a divorced middle class Chinese bus driver with - No, I hear
Japan is really getting into this divorce thing. OK, a divorced
middle class Japanese auto worker with no children! Imagine him
asking for a raise:
"I want more money! Chinese make more money raising rice than
I do! Even Germans eating turnips do. Give me money!"

Yeah - right.....

Mismatched Zo Connectors
 

Richard Clark wrote:
Cecil Moore wrote:
I have corrected it in another posting...

Blah, blah, blah, tailored of course to a different problem. SOS

Yes, tailored to a configuration that is possible
(Thevenin source) rather than the previous impossible
one (100 watts into an infinite impedance).

So far, Jim has refused to discuss all possible
configurations and seems to prefer only the impossible
ones. One wonders why.
--
73, Cecil http://www.qsl.net/w5dxp