Dave wrote:


keep going guys! only 50 more messages to hit 1000 in this thread! thats
got to be a record for r.r.a.a! how many more ways can cecil and roy go
around in circles with phases. can we get roger back in the fray? that
would be good for another dozen or so anyway! jim lux hasn't contributed
recently, where did he drop out? and where, oh where, is art??????????


Just a phase they are going through.............



- 73 d eMike N3LI -

Michael Coslo wrote:
Just a phase they are going through.............

Exactly what is the reference for that phase? :-)
--
73, Cecil http://www.w5dxp.com

On Dec 20, 11:02 am, Cecil Moore wrote:
Michael Coslo wrote:
Just a phase they are going through.............

Exactly what is the reference for that phase? :-)

Fire hydrant.

-------------------

35 messages to go.

Keith Dysart wrote:
On Dec 20, 11:02 am, Cecil Moore wrote:
Michael Coslo wrote:
Just a phase they are going through.............
Exactly what is the reference for that phase? :-)

Fire hydrant.

Hey Keith, have you been able to disprove my figures
in my other thread "Please verify (or disprove)"?
If not, why not? Seems it would be an ideal time
to nail me to the wall with some math that disagrees
with mine.
--
73, Cecil http://www.w5dxp.com

Tom Donaly wrote:
jim lux
hasn't contributed recently, where did he drop out?

Nothing really to contribute..
Jim,w6rmk

Jim Lux wrote:
Tom Donaly wrote:
jim lux hasn't contributed recently, where did he drop out?

Nothing really to contribute..

Jim, would you please check my math in the thread titled,
"Please verify (or disprove)"? Appreciate it.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
I don't blame you for trying your best to suppress the
technical facts by hiding things in a black box

If that is what you wish to believe, then there is no way to convince
you otherwise.

but now the
whole world is aware of your attempted suppression of
technical facts, not a good reputation to have for a technical
editor.

So you accuse; but I'm content to let everyone else be the judge.


--

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

On Dec 20, 4:32 am, Ian White GM3SEK wrote:
Cecil Moore wrote:
But the rules for black boxes do not allow measurements
on the inside. This is how they help clarify the thinking.

So instead of sweeping technical facts under the rug,
you hide them in a black box. In both cases, the only
apparent purpose is to maintain ignorance.

It seems that whatever part of the system you don't
understand, you draw a black box around it so you
don't have to understand it.

No, it is a perfectly normal technique to test a theory or model. The
black box reveals just enough information to solve the problem, and
nothing more.

In this particular case, the impedance at the terminals of the black box
is the only *necessary* information to solve the transmission-line
problem (in the steady state, at one frequency). It is not necessary to
know how that impedance was created.

But Ian,

Suppose the box is labeled -j567 ohms.

Then I ask, "at what frequency is this impedance -j567?".

I find that the impedance for -j567 ohms is 4 Mhz.

Now I take a length of 600 ohm VF = 1 transmission line and vary the
length until I am at resonance with whatever is in the black box at 4
MHz. Resonance would imply 90 degrees total phase shift.

My measurement shows that the length of 600 ohm line to cause this
effect is 43 degrees.

Assuming my measurement is correct, doesn't that tell us a little more
about what is inside the box? It isn't just "any" -j567 ohm impedance
that can cause resonance with a 43 degree 600 ohm line. It is probably
not a discreet capacitor, it would likely be some sort of transmission
line or something that that has 10 deg length, correct?

With a few more measurements, we can determine the Zo of the
transmission line that "appears' to be in the black box, correct and
essentially verify that it a transmission line. We should be able to
both measure and calculate Zo.

If we choose our independent measurements carefully enough, we should
be able to define exactly what is in the black box with only 2
terminals.

I agree you need more than a smith chart (which was where I made my
mistake before).

AI4QJ

Ian White GM3SEK wrote:
Cecil Moore wrote:
I don't blame you for trying your best to suppress the
technical facts by hiding things in a black box

If that is what you wish to believe, then there is no way to convince
you otherwise.

It's not what I believe, Ian, it is what you did right
here in front of God and everybody. There was absolutely
no reason to introduce a black box concept unless you
were trying to hide something embarrassing inside the
black box. That embarrassing something is obviously
the phase shift at an impedance discontinuity which you
are trying your best to suppress.

but now the
whole world is aware of your attempted suppression of
technical facts, not a good reputation to have for a technical
editor.

So you accuse; but I'm content to let everyone else be the judge.

If you aren't trying to suppress technical facts, then
please perform the math on my other thread,
"Please verify (or disprove)" and post your results
whether or not they agree with my results. By refusing
to respond, you will be enforcing my worst fears about
your ulterior motives, i.e. to suppress the technical
facts about that phase shift.
--
73, Cecil http://www.w5dxp.com

Jim Lux wrote:
Tom Donaly wrote:
jim lux
hasn't contributed recently, where did he drop out?

Nothing really to contribute..
Jim,w6rmk

I didn't write that, Dave did.
73,
Tom Donaly, KA6RUH