On Mon, 24 May 2004 16:40:44 -0500, "Steve Nosko"
wrote:
This is an interesting twist, Tam. I think if this were the case, then
there would be MORE power dissipated in the Tx

Hi Steve,

And why would that be?

73's
Richard Clark, KB7QHC

Dave Shrader wrote:
Cecil Moore wrote:

snip

For what it is worth, I believe that the first homo sapien
originated about a quarter of a million years ago and was
a female with dominant genes.
--
73, Cecil http://www.qsl.net/w5dxp


My wife has me convinced that ALL women have the dominant genes!!!!

I prefer women without jeans, thankyouvermuch!

- Mike KB3EIA -

Richard Clark wrote:

wrote:
You asked - I answered.

Did you? What was the original question?

I don't know. I wasn't around 7 billion years ago.



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Richard Clark wrote,

On Mon, 24 May 2004 15:28:40 -0500, Cecil Moore
wrote:
I am sure that our solar system and homo sapiens didn't exist
when the original question was asked.
So the question is which came first, the homo or the solar system?


Homos before Helios, or Helios before homos? That's a profound
question which I'll have to think about over my after-dinner port. On
the surface it looks about as meaningful as "turkeys from Turlock,"
but first impressions are sometimes deceiving.
73,
Tom Donaly, KA6RUH

Cecil wrote,

Richard Clark wrote:

wrote:
I am sure that our solar system and homo sapiens didn't exist
when the original question was asked.

So the question is which came first, the homo or the solar system?

For what it is worth, I believe that the first homo sapien
originated about a quarter of a million years ago and was
a female with dominant genes.
--
73, Cecil http://www.qsl.net/w5dxp



Yes, she married Org Orgluk and they had a bunch of halfwit kids who sired
the human race.
73,
Tom Donaly, KA6RU

Richard Clark wrote:

On Mon, 24 May 2004 14:06:28 -0500, Cecil Moore
wrote:

What was the original question? [accredited stock response]

When totally ignorant, divert the issue as long as possible.
Why am I not surprised?

Are you sure this is the original question? [accredited stock
response]

Richard

Your earlier comment on things was quite accurate. This thread is
hilarious!

tom
K0TAR

On Mon, 24 May 2004 18:37:09 -0500, Cecil Moore
wrote:
I don't know. I wasn't around 7 billion years ago.
We were beginning to wonder.

"Steve Nosko" wrote in message
...

"Tam/WB2TT" wrote in message
...

"Richard Fry" wrote in message
.........................
...............................
Concept below

However this is not an accurate model of a transmitter.

For an example, take an old Heathkit DX-100 generating a measured 180
watts
of CW RF into a matched 50 ohm load. To do this, it does NOT also
dissipate
180 watts of RF into some "virtual" internal RF load in the DX-100.
In
fact, the PAs and power supply in the DX-100 could not produce a total
RF
output power of 360 watts without exceeding their ratings.

The dissipation in the PA is essentially related only the DC to RF
conversion efficiency of the PA, which in this case probably is about
75%,
max (Class C). So a PA input power of about 240 watts DC is required
to
produce 180 watts of RF output power. The other 60 watts of plate
input
power is converted to heat by the PA tube anodes.

The entire RF output generated by the PA stage is applied virtually
100%
to
the output connector. How much of that is absorbed by the load
connected
there is a function of load SWR and system losses.

- RF
There is a Motorola ap note that agrees with what Richard is saying. To
paraphrase it, if the the DX100 had an output impedance of 50 Ohms, then
the
overall efficiency would be 37.5%.

Unfortunately I can't read all the digressions in the thread. I skim
by
author...

This is an interesting twist, Tam. I think if this were the case,
then
there would be MORE power dissipated in the Tx than Mr. Fry is saying -
making the situation worse. By that, I mean, getting further from what is
going on. I think this goes in the wrong direction. I believe the flaw
is
believing that the Rs=RL must exist for the transmitter.

That is what I am saying. The efficiency goes from 75% to 37.5%; so, there
is more power dissipated in the TX.

Tam/WB2TT
--
Steve N, K,9;d, c. i My email has no u's.

Richard Clark wrote:

On Sun, 23 May 2004 02:07:13 GMT, "Henry Kolesnik"
wrote:


I know that any power not dissipated by an antenna is reflected back to the
transmitter. Then the transmitter "reflects" this reflection back to
antenna, ad nauseum until its all gone. I also know that a short or an open
is required to reflect power and I'm searching for which it is, an open or a
short. I'm inclined to think it's a virtual open but I'm at a loss to
understand that and I wonder if someone has a good explanation or analogy
and some math wouldn't hurt.
tnx
Hank WD5JFR



Hi Hank,

At last count there are 130 responses to this post, this is #131, and
the question still hasn't been answered.

When energy or power is transmitted in any medium where the wavelength
and the length of the transmission medium are significant percentages of
one another some energy/power is reflected at any discontinuity in the
transmission medium. The reflected energy/power may be re-reflected if a
discontinuity exists in the backward path.

The simplest example that we can all understand is the common case of
the echo!! H E L L O ! .... HELLO ! .... hello ! .... etc. The
energy/power is re-reflected many times until we can't hear it. But is
is still re-reflecting at sub-audible levels until 100% dissipation
occurs. As long as the discontinuities exist the echoes exist!

DD, W1MCE


What you describe as reflection and re-reflection occurs between the
mismatched antenna and the tuner that has been adjusted to minimize
power returned to the transmitter. The sole function of the tuner is
to keep this power from being dissipated by the transmitter (common
experience of arcing, denoting a voltage reflection, or thermal
runaway, denoting a current reflection). The "virtual" reflection
(offered by the tuner) is generally know as the complex conjugate of
the remote load, seen at the near end of the line through which it is
returning. This means that the line transforms the phase and
amplitude of the reflection, and the tuner's job is to invert that
relationship to counteract it, and return it to the antenna.

There are both wave descriptions of this process, and lumped circuit
equivalents. Both work, and both describe the same process from
different points of view. One does not negate the other's validity
(unless, of course, you attempt to mix the points of view and demand
consistency in terms - a frequent rhetorical trap here).

There will no doubt be a flurry of denials to this simple example with
contortions of logic to match. As for the math, you will find it by
the reams, once you've been overwhelmed with the arcana of hyperbolic
descriptions of a novel physics that have to proceed its proof.

Keep your eye on how your literal points in your question go abandoned
with these arcane theories.

73's
Richard Clark, KB7QHC

On Tue, 25 May 2004 01:45:19 GMT, Dave Shrader
wrote:
At last count there are 130 responses to this post, this is #131, and
the question still hasn't been answered.

Hi Dave,

Well, actually, it has been answered sufficiently, apparently it
hasn't been understood - quite a gulf between those two positions. As
such, your response doesn't necessarily constitute an answer either,
that is, until the gulf is spanned.

73's
Richard Clark, KB7QHC