On Thu, 01 Mar 2007 09:49:52 GMT, Owen Duffy wrote:

Reminding you that your question was "What is the loss in the line?",
check your own post.

Hi Owen,

Can you offer why I should? Well, I suppose not or you would have.

However, I am one to never turn aside a suggestion and I did review
everything (except my own quote - I've repeated it enough, haven't I?)
and I will respond to that review within the body of this text.

Well, you posted an answer, not a solution. It wouldn't have been your
solution anyway, because it looks like it is copied straight out of a
book.

Does it being someone else's solution make any difference to the
outcome? Owen, your comment reveals a prejudice by implication.
Copying it right out has removed any issue of authority has it not? It
has also removed any issue of accuracy too - if you accept that
authority. Ultimately, having copied it out makes for the best
resolution. Having copied it out, and offering the citation, gives us
both access to the chain of evidence. Did I withhold or otherwise
linger with the citation? You asked for my solution and I immediately
offered both.

Ironically, does your suggestion that
It wouldn't have been your solution anyway
mean you would suspect I would have come up with a different answer?
That is, ascribing to me the quality of being able to get it right
instead? That would be generous, thank you. However, it appears I
fell short of that mark (and may have been the intent of your
elliptical pat on the back).

Looking at Reference Data for Engineers, Sixth Edition, p24-12, Example 3
(which is the same as the problem you posed), they give the answer as
3.27dB.

A simple review of example four distinctly reveals the details to the
problem I posed; example three contains only some of them. Example 3
is a subset of example 4 (as that example dwells on at great length).

However, example 4 does have one notable difference, it asks:
"What is mismatch loss between the generator and the line?"
for which the answer is:
"1.62 dB"

Ah, the devil is in the details. Continuing from example 4:
"The transducer loss is found by using the results
of 3 and 4 in (4). This is
1.27 + 2.00 + 1.62 = 4.9 decibels"

I am happy that my answer rounded to 3.3dB is correct.

Congratulations. You may note in my earlier correspondence I allowed
exactly that.

The source resistance has no influence over the line loss at all.

Upon review of my own reference (not the recommendation you offer
above) I must concur. I was trapped by what I have already described
as being the classic confusion between systems of match and loss. My
solution was not for the loss in the line, but for transducer loss,
and specifically for the inclusion of mismatch loss within the
transducer loss. All caloric, but mis-ascribed to the line loss.

You posed this problem as difficult and one that no one has ever got
right. No wonder, you have a different answer to the the book!

Well, in fact my answer conforms exactly to the book. The problem is
not one of inexactitude, it is of poor referencing. As to the matter
of no one else having ever got it right, no one even consulted the
book - even partially. You can count yourself among a population of
one and hashing it through served us well.

73's
Richard Clark, KB7QHC