Dan Bloomquist wrote in
:

Owen Duffy wrote:

Dan Bloomquist wrote in
news:4khKh.5006$ya1.3770 @news02.roc.ny:


Owen Duffy wrote:


Dan Bloomquist wrote in
:



Are the principles that apply to this example inconsistent with
the general case (eg dc, ac, transient, steady state etc)?

Yes.


I would have thought the answer was NO, the principles are *not*
inconsistent with the general case.

Hi Owen,
See the example I posted where a pulse is sent down the line. In that
case all the energy is dissipated in the source resistor.


Dan, I don't deny there may be cases where that may happen, but it is
not true that reflected power is necessarily dissipated (or partly
dissipated) in the equivalent source resistance.

And I answered accordingly when you asked the very question, I agreed
with you. And I showed just that in the step example of a previous
post.


Dan we are agreed!

My conclusion is that the view put by some that reflected power is
(necessarily) fully or partly dissipated in the PA equivalent source
resistance, (possibly overheating the PA,) is a simplistic view, the
explanation doesn't apply in general and although apparently appealing,
it is wrong.

Owen

Owen Duffy wrote:
My conclusion is that the view put by some that reflected power is
(necessarily) fully or partly dissipated in the PA equivalent source
resistance, (possibly overheating the PA,) is a simplistic view, the
explanation doesn't apply in general and although apparently appealing,
it is wrong.

The question is: Does any reflected joules/second ever
get dissipated in the PA? To ascertain the answer, one
must calculate the interference patterns in both directions.
If the energy is not dissipated anywhere else, it is
dissipated in the PA.
--
73, Cecil, w5dxp.com

On Thu, 15 Mar 2007 20:43:54 GMT, Owen Duffy wrote:

My conclusion is that the view put by some that reflected power is
(necessarily) fully or partly dissipated in the PA equivalent source
resistance, (possibly overheating the PA,) is a simplistic view, the
explanation doesn't apply in general and although apparently appealing,
it is wrong.

Hi Owen,

Was your example any more complex, or general? In fact it was heavily
tailored for one simplistic answer only wasn't it? The subject line
informs us it was.

You have in the past used the dictum that one counter-example
devastates a poor hypothesis. What you have here is a two degree
answer that fails for the other 358 degrees, where a one word answer
is insufficient.

Reduce this to chance for haphazard line lengths and a spectrum of
loads, then there's a 50% probability of cooling (absurd of course)
and a 50% probability of heating. Reducing that generality to one
word would give us "maybe."

The subject becomes 99.44% uninforming.

73's
Richard Clark, KB7QHC